Chapter 8: Chemistry of Alkynes (C n H 2n-2 )

Size: px
Start display at page:

Download "Chapter 8: Chemistry of Alkynes (C n H 2n-2 )"

Transcription

1 hapter 8: hemistry of Alkynes ( n 2n-2 ) Bonding & hybridization Both are sp-hybridized Bond angles = 180 o 1 σ + 2 π bonds Linear around lassification R R R' σ bond energy: 88 kcal/mol π bond energy: 56 kcal/mol No conformers No geometric isomerism While cycloalkanes and alkenes are common, alkynes seldom appear in a ring. Why? terminal alkyne internal alkyne Nomenclature IUPA: Same rules apply as for alkenes, except that names end in yne. The triple bond takes precedence in the numbering of carbons in the main chain. ommon naming: = acetylene Many alkynes are named as derivatives of acetylene by adding a prefix indicating the alkyl groups attached on each side of the = Ex: 3 3 = dimethylacetylene Molecule shape and effect on physical properties: Linearity of alkynes increases van der Waals contact, strengthens London forces Boiling points of alkynes are slightly higher than alkenes of similar MW Solubility properties are similar to other hydrocarbons

2 Preparation of Alkenes and Alkynes Alkenes: 1) Thermal cracking of alkanes: used to produce small alkenes likeethylene 900 o = Disadvantage: Not useful for preparing larger alkenes with specific structures 2) Base-catalyzed elimination from RX: Position of double bond is predictable KO 3 2 O 3 3 3) Acid-catalyzed dehydration of alcohols 3 + K + 2 O Zaitsev s rule: The most substituted alkene is formed preferentially Alkynes 3 O 3 PO 4 heat major O minor 1) Dehydrohalogenation of a vicinal dihalide: 3 3 2KO 3 2 O ) Dehydrohalogenation of vinylic alkyl halides: l 3 3 1) 2 NaN 2 2) 3 O N 3 + Nal

3 Reactivity of alkynes toward electrophiles: Like alkenes, alkynes have π bonds that act as nucleophiles, therefore electrophilic addition is a major reaction pathway. Some aspects of alkyne reactivity and mechanisms can be explained by comparing the electronegativities of carbon atoms involved in hybridization: sp > sp 2 > sp 3 increasing electronegativity Why? The closer the atom holds its electrons, the greater its electronegativity. This in turn affects the mechanism and type of intermediate that forms during electrophilic addition. Electrophilic addition to alkynes may involve a vinylic cation, or a more complex arrangement where the positive charge is spread out: -l 2 +l - l -l δ l - l l The unsubstituted vinylic cation is unstable, due to the + charge on an sphybridized (would be an sp 2 -hybridized in regular carbocations) Substituted vinylic carbocations are more stable due to e- donation arbocation stability (revisited): 3 o > 2 o > 1 o = 2 o vinylic >> 1º vinylic

4 1. Electrophilic additions to alkynes A. ydrohalogenation and halogenation reactions: Follow Markovnikov orientation Proceed with anti stereochemistry of addition The electrophile and the nucleophile add from opposite sides of the carbon-carbon bond (trans orientation); one geometric isomer predominates Ex: l 2 3 l 2 3 l (E)-2,3-dichloro-2-pentene anti and syn addition of reagents results in different isomers! Will continue with addition of a second equivalent to the newly-formed alkene when an excess of electrophile is present: Ex: l l 3 l 2 3 A geminal dichloride l

5 B. ydration reactions of alkynes 1. Addition of water to an alkyne might produce an alcohol, as for alkenes: O O Internal alkyne An alkene with O group on = : an enol owever, enols are not very stable. The pi electrons prefer the O bond, especially in acid solution. Keto-enol tautomerism occurs to produce =O: O O Enol Ketone Tautomers = isomers which differ in placement of the double bond and atom The keto form is more stable and will be the major product formed in a hydration. Terminal alkynes do not easily undergo acid-catalyzed hydration. 2. Mercury-catalyzed hydration (similar to oxymercuration of alkenes) will produce ketones, even with terminal alkynes 3 2 O, + gso 4 3 O 2 3 O 3 Markovnikov 2-propanone (a ketone) 3. ydroboration-oxidation: Anti-Markovnikov orientation results in formation of aldehydes. With terminal alkynes, a bulky alkylborane may be used 3 1) B 3 /TF or disamylborane 2) O-, 2 O 2, 2 O 3 2 O Anti-Markovnikov Propanal (an aldehyde)

6 . Addition of hydrogen to produce alkenes or alkanes (You may have noticed a theme: what alkenes can do, alkynes can do twice) ydrogenation: When regular Pt catalyst is used, two additions occur 1equivalent 3 3 2,Pt 3 3 1moreequiv 2,Pt Alkyne Alkene (syn-addition) Alkane 2- butyne cis-2-butene butane or (Z)-2-butene To produce alkenes, addition of the second equivalent of 2 can be avoided by using a partly inactivated metal catalyst ( poisoned palladium ) to only deliver 1 equiv. 2 : Lindlar s catalyst = Pd on ao 3, treated with lead acetate and quinoline Lindlar's catalyst 3 3 atalytic hydrogenation only produces cis isomers; trans-alkenes require a different approach: 3 3 Na or Li Liquid N 3 Sodium reacts more readily with alkyne than = (no second addition to the alkene), producing a vinylic anion (R 2 = R:-) The vinylic anion can be attacked from either side by the nucleophile N 3 Since the trans form of vinylic anion is more stable; the major product is trans. D. Oxidative cleavage: Oxidation of alkynes: bond is cleaved, yielding carboxylic acids or O 2 : 3 3 Internal: Terminal: R R' R O O KMnO 4 or O 3 + KMnO 4 or O 3 R R O O O + R' O O O

7 arbonyl compounds from alkynes:

8 Acidity of terminal alkynes Recall that electronegativities of atoms follow this trend: sp > sp 2 > sp 3 ow does this affect the acidity of a hydrogen atom bonded to the alkyne? > > 3 3 pka = 25 pka = 44 pka = 50 In the grand scheme, acetylenes are more acidic than ammonia but less than water. 3 3 < 2 = 2 < N 3 < = < 2 O < F Increasing acidity Increasing basicity > 2 =- > N 2 - > =:- > O- > F- In the presence of a very strong base, a terminal alkyne forms a conjugate base: an acetylide ion: NaN 2 N Na + +N 3 3 Acid, pka = 25 conjugate base, pka = 36 The base must be stronger than the acetylide ion (itself a pretty strong base) Amide ion is used in the form of sodium amide in liquid ammonia: NaN 2 /N 3 Note: The weak acidity of the bond in terminal alkynes is unique among hydrocarbons in alkenes, alkanes and internal alkynes do not behave as acids.

9 New concept: Building a arbon Skeleton A chain-lengthening alkylation reaction Most of the reactions of hydrocarbons with pi bonds that we have encountered so far mainly result in new functional groups: --Electrophilic addition reactions of alkenes or alkynes which produce alkyl halides --ydration reactions involving addition of water or other oxygen-containing reagents to produce alcohols --ydrogenation reactions which saturate alkenes & alkynes (adding more ) Acetylide ions can undergo reactions in which new carbon-carbon bonds form, resulting in a longer carbon chain. The mechanism is not addition, but a nucleophilic substitution in which the acetylide ion replaces the halide: R Na + + R' R R' +Na Acetylide ion Primary alkyl halide Larger alkyne Alkynes are extremely useful starting points for synthesis because you can use them to build a longer chain/transform to another functional group by preparing acetylides: 3 2 NaN 2 2 liq N 3 3 Na l

10 Multistep synthesis: Figuring out how to prepare a compound step by step Points to keep in mind when designing the synthesis of a compound: 1. There are probably several pathways to get you to your goal. (In the lab, that means the shortest pathway with the most product yield and cheapest reagents!) 2. Reactions in the textbook are grouped by reactant, not necessarily by product. You may have to consider several different classes of compounds (functional groups) as reactants. It helps to compile your own list, adding reactions as you learn them. 3. A retrosynthetic approach is most effective: Think of each reaction you learned in reverse: the product becomes the reactant! Start each problem by figuring out what to do last. 4. Work your way backwards to plan each step, focusing on making the necessary functional group or other changes in the molecule until you get to the suggested (or cheapest) starting reagents. 5. Next, work back through your proposed steps in the forward direction, taking into account both major and minor products. Your desired product in each step should be the major one. 6. Keep mechanisms in mind, especially where rearrangements are possible or regioselectivity is the rule. Practice makes perfect: the more problems you solve whether working in the forward or reverse direction, the easier it is to see patterns of reactivity and use them.

11

An alkyne is a hydrocarbon that contain a Carbon carbon triple bond. Acetylene, the simplest alkyne, widely used in industry for the synthesis of

An alkyne is a hydrocarbon that contain a Carbon carbon triple bond. Acetylene, the simplest alkyne, widely used in industry for the synthesis of Alkynes An alkyne is a hydrocarbon that contain a Carbon carbon triple bond. Acetylene, the simplest alkyne, widely used in industry for the synthesis of acetaldehyde, acetic acid, vinyl chloride O O H

More information

Alkynes and Their Reactions

Alkynes and Their Reactions Alkynes and Their Reactions Naming Alkynes Alkynes are named in the same general way that alkenes are named. In the IUPAC system, change the ane ending of the parent alkane name to the suffix yne. Choose

More information

Alkynes contain a C C triple bond

Alkynes contain a C C triple bond Chapter 8: Alkynes: an introduction to organic synthesis Alkynes contain a C C triple bond Acetylene: H-C C-H is the common name for ethyne, used as a torch fuel Alkyne nomenclature follows normal hydrocarbon

More information

Alkynes: An Introduction to Organic Synthesis

Alkynes: An Introduction to Organic Synthesis Alkynes: An Introduction to Organic Synthesis Alkynes Hydrocarbons that contain carbon-carbon triple bonds Acetylene, the simplest alkyne is produced industrially from methane and steam at high temperature

More information

Stability of vinyl C+ is about the same as H 3 C+. NOT ASSISTED!

Stability of vinyl C+ is about the same as H 3 C+. NOT ASSISTED! rganic hemistry Interactive Notes hapter 8: Alkynes Naming Alkynes Structure ommon Name IUPA Acetylene ethyne methyl acetylene propyne dimethyl acetylene -butyne ethyl acetylene -butyne =- as substituent

More information

Alkynes: An Introduction to Organic Synthesis. Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8

Alkynes: An Introduction to Organic Synthesis. Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8 Alkynes: An Introduction to Organic Synthesis Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8 Alkynes! Hydrocarbons that contain carbon-carbon triple bonds! Acetylene, the simplest alkyne

More information

Learning Guide for Chapter 11 - Alkynes

Learning Guide for Chapter 11 - Alkynes Learning Guide for Chapter 11 - Alkynes Introduction to s - p 1 ybridization and geometry, Reactivity, Types of s, Cyclic s, Physical properties, Spectroscopy, Acidity, Natural occurrence and uses Nomenclature

More information

Chapter 7 - Alkenes and Alkynes I

Chapter 7 - Alkenes and Alkynes I Andrew Rosen Chapter 7 - Alkenes and Alkynes I 7.1 - Introduction - The simplest member of the alkenes has the common name of ethylene while the simplest member of the alkyne family has the common name

More information

Chapter 13 Alkenes and Alkynes

Chapter 13 Alkenes and Alkynes hapter 13 Alkenes and Alkynes Types of Bonds Alkanes and haloalkanes consist of atoms held together by bonds. These can also be called sigma bonds (σ bonds) which means that the orbitals of each atom overlap

More information

Organic Chemistry Practice Exam #4

Organic Chemistry Practice Exam #4 rganic Chemistry 32-235 Practice Exam #4 Part 1: 1. The correct IUPAC name for the following structure is. C 2 CC 2 C C 2 5-hexen-3-ol 3-hydroxy-5-hexene (E) 4-hydroxy-1-hexene 1-hexen-4-ol (D) Isohexen-3-ol,

More information

Alkenes and Alkynes. Chapter 1.2

Alkenes and Alkynes. Chapter 1.2 Alkenes and Alkynes Chapter 1.2 Unsaturated Hydrocarbons Alkenes and alkynes are unsaturated hydrocarbons An alkene is a hydrocarbon that contains at least one carbon-carbon double bond An alkyne is a

More information

Chapter 6 Alkenes I. IUPAC Rules for Alkene and Cycloalkene Nomenclature

Chapter 6 Alkenes I. IUPAC Rules for Alkene and Cycloalkene Nomenclature hapter 6 Alkenes I Naming Alkenes General Rule: replace ane with ene. No. of arbons IUPA Name ommon Name Formula n 2n Structure 2 Ethane ethylene 2 4 2 = 2 3 Propene propylene 3 6 2 = 3 4 1-Butene butylene

More information

Alcohols (R-OH) and Alkyl halides R-X (X = F, Cl, Br, I) Alcohols. Suffix:

Alcohols (R-OH) and Alkyl halides R-X (X = F, Cl, Br, I) Alcohols. Suffix: Alcohols (R-O) and Alkyl halides R-X (X = F, Cl,, I) Alcohols Alcohols contain a R-O functional group. Primary, secondary or tertiary? O O O Nomenclature: Suffix: numbering scheme: The number locating

More information

Electrophilic Addition Reactions

Electrophilic Addition Reactions Electrophilic Addition Reactions Electrophilic addition reactions are an important class of reactions that allow the interconversion of C=C and C C into a range of important functional groups. Conceptually,

More information

Chapter 4: Alkenes and Alkynes. Degree of unsaturation

Chapter 4: Alkenes and Alkynes. Degree of unsaturation hapter 4: Alkenes and Alkynes Unsaturated ydrocarbon: ontains one or more carbon-carbon double or triple bonds or benzene-like rings. Alkene: contains a carbon-carbon double bond and has the general formula

More information

very strong bases very strong nucleophiles

very strong bases very strong nucleophiles hapter 14: rganometallic ompounds - eagents with carbon-metal bonds 14.1: rganometallic Nomenclature (please read) 3 -Li Butyllithium Mg vinylmagnesium bromide ( 3 ) u - Li Dimethylcopper lithium 14.:

More information

Alkenes: Alkynes: Example: What are all the structural possibilities for C 3 H 4? Unsaturated hydrocarbons: Bonding Patterns of Multiple Bonds

Alkenes: Alkynes: Example: What are all the structural possibilities for C 3 H 4? Unsaturated hydrocarbons: Bonding Patterns of Multiple Bonds Chapter 3 Organic Chem: Alkenes & Alkynes Don t need to know the following reactions found on summary pages 110-112: 1. Hydroboration-Oxidation 2. Cycloaddition to Conjugated Dienes 3. Alkyne reaction

More information

Study Guide Chapters 19-20 Alkanes, Alkenes and Alkynes

Study Guide Chapters 19-20 Alkanes, Alkenes and Alkynes Study Guide Chapters 19-20 Alkanes, Alkenes and Alkynes 1) Carbon-Carbon Bonding in Alkanes (C-C), Alkenes (C=C) and Alkynes (C C). Understand the hybridization of atomic orbitals (ground state promotion

More information

ALCOHOLS: Properties & Preparation

ALCOHOLS: Properties & Preparation ALLS: Properties & Preparation General formula: R-, where R is alkyl or substitued alkyl. Ar-: phenol - different properties. Nomenclature 1. ommon names: Name of alkyl group, followed by word alcohol.

More information

Addition Reactions of Carbon-Carbon Pi Bonds - Part 1

Addition Reactions of Carbon-Carbon Pi Bonds - Part 1 Addition eactions of arbon-arbon Pi Bonds - Part 1 3 δ+ 2 δ 3 3 3 + 2 3 2 3 What Is an Addition eaction? Addition reaction: Atoms or groups are added to opposite ends of a pi bond. X Y Why should I study

More information

ALKENES, ALKYNES and AROMATIC COMPOUNDS Chapter 13

ALKENES, ALKYNES and AROMATIC COMPOUNDS Chapter 13 ALKENES, ALKYNES and AROMATIC COMPOUNDS Chapter 13 13.1 Introduction An ALKENE is a hydrocarbon with a double C bond that looks like C=C An ALKYNE is a hydrocarbon with a triple C bond that looks like

More information

Chapter 25 The Chemistry of Life: Organic Chemistry. 25.1 Some General Characteristics of Organic Molecules

Chapter 25 The Chemistry of Life: Organic Chemistry. 25.1 Some General Characteristics of Organic Molecules Chapter 25 The Chemistry of Life: Organic Chemistry general characteristics of organic molecules introduction to hydrocarbons alkanes unsaturated hydrocarbons functional groups: alcohols and ethers compounds

More information

Principles of Drug Action 1, Spring 2005, Alkynes, Jack DeRuiter HYDROCARBON STRUCTURE AND CHEMISTRY: ALKYNES

Principles of Drug Action 1, Spring 2005, Alkynes, Jack DeRuiter HYDROCARBON STRUCTURE AND CHEMISTRY: ALKYNES YDRARB STRUTURE AD EMISTRY: ALKYES I. Introduction ydrocarbons are organic compounds consisting of - and - bonds. arbon has a valence of four and thus requires four electrons or bonds to complete its octet

More information

Protonation. favored H 3 O + R O O H

Protonation. favored H 3 O + R O O H arboxylic Acids arboxylic acids have one property that distinguishes them from most other organic compounds they re acidic. Now not as acidic as fuming sulfuric acid, but still pretty darned acidic. The

More information

But in organic terms: Oxidation: loss of H 2 ; addition of O or O 2 ; addition of X 2 (halogens).

But in organic terms: Oxidation: loss of H 2 ; addition of O or O 2 ; addition of X 2 (halogens). Reactions of Alcohols Alcohols are versatile organic compounds since they undergo a wide variety of transformations the majority of which are either oxidation or reduction type reactions. Normally: Oxidation

More information

Under acidic conditions, carbonyl compounds are protonated on O first, then weak base deprotonates at the α-c to give enol.

Under acidic conditions, carbonyl compounds are protonated on O first, then weak base deprotonates at the α-c to give enol. Substitution reactions of carbonyl compounds at the α-position Carbonyl compounds are acidic at α-c (e.g. C 2 C ); this is because of the electrophilic nature of carbonyl C= bond. The pka values of simple

More information

Ozonolysis of Alkenes

Ozonolysis of Alkenes zonolysis of Alkenes 1 When 2-methyl-2-pentene reacts with ozone, the initial 1,2,3-trioxolane product is 144, but this rearranges to ozonide 145. If 145 is treated with hydrogen peroxide as above, one

More information

Chapter Thirteen. Alkenes, Alkynes, and Aromatic Compounds

Chapter Thirteen. Alkenes, Alkynes, and Aromatic Compounds Chapter Thirteen Alkenes, Alkynes, and Aromatic Compounds Saturated: A molecule whose carbon atoms bond to the maximum number of hydrogen atoms. Unsaturated: A molecule that contains a carbon carbon multiple

More information

ORGANIC COMPOUNDS IN THREE DIMENSIONS

ORGANIC COMPOUNDS IN THREE DIMENSIONS (adapted from Blackburn et al., Laboratory Manual to Accompany World of hemistry, 2 nd ed., (1996) Saunders ollege Publishing: Fort Worth) Purpose: To become familiar with organic molecules in three dimensions

More information

Carbocations Based on a Fall 2001 Chemistry 30BH Honors project by Patricia Young

Carbocations Based on a Fall 2001 Chemistry 30BH Honors project by Patricia Young arbocations Based on a Fall 2001 hemistry 30B onors project by Patricia Young Tutorial ontents A. Introduction B. arbocation lassification. arbocation Stability D. arbocation Formation E. Three Fates of

More information

Chapter 22 Carbonyl Alpha-Substitution Reactions

Chapter 22 Carbonyl Alpha-Substitution Reactions John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 22 Carbonyl Alpha-Substitution Reactions The α Position The carbon next to the carbonyl group is designated as being in the α position Electrophilic

More information

19.2 Halogenation 4/18/2012. Is the reaction substitution, elimination, addition or pericyclic?

19.2 Halogenation 4/18/2012. Is the reaction substitution, elimination, addition or pericyclic? 19.1 Introduction to Electrophilic Aromatic Substitution In Chapter 18, we saw how aromatic C=C double bonds are less reactive than typical alkene double bonds. Consider a bromination reaction: 19.1 Introduction

More information

Final Examination, Organic Chemistry 1 (CHEM 2210) December 2000 Version *A* A. B. C. D.

Final Examination, Organic Chemistry 1 (CHEM 2210) December 2000 Version *A* A. B. C. D. Final Examination, rganic hemistry 1 (EM 2210) December 2000 Version *A* 1. What are the hybridization of, and the geometrical shape around, the nitrogen atom in the following molecule? N 3 3 A. sp, linear

More information

CHEMISTRY 263 Module7. Hydrogenation of Alkenes Text Sections: Homework Chapter7: Module8. Alkenes and Alkynes II: Addition reactions

CHEMISTRY 263 Module7. Hydrogenation of Alkenes Text Sections: Homework Chapter7: Module8. Alkenes and Alkynes II: Addition reactions 1 CHEMISTRY 263 Module7. Hydrogenation of Alkenes The Function of the Catalyst - Syn and anti- addition Hydrogenation of Alkynes - Syn- addition of hydrogen: Synthesis of cis-alkenes - Anti addition of

More information

Chem 101: General Chemistry Lecture 10 - Organic Compounds: Alkanes

Chem 101: General Chemistry Lecture 10 - Organic Compounds: Alkanes hem 101: General hemistry Lecture 10 - Organic ompounds: Alkanes I. arbon: The element of organic molecules A. Organic compounds are compounds that contain the element carbon 1. There are a few exceptions

More information

Chemistry B11 Chapter Alcohols, Ethers, Thiols and Chirality

Chemistry B11 Chapter Alcohols, Ethers, Thiols and Chirality hemistry B11 hapter 14-15 Alcohols, Ethers, Thiols and hirality Alcohols: the functional group of an alcohol is an hydroxyl group -O. 3 O 3 2 2 O Naming alcohols: 1. Select the longest chain that contains

More information

CHEM 341: Organic Chemistry I

CHEM 341: Organic Chemistry I EM 341: rganic hemistry I at North Dakota tate University Final Exam - tudy Guide Reactions to know ubstitution of Alcohols R X R X N 1 ubstitution - N 2 ubstitution 3 carbocation best 2 carbocation ok

More information

methyl RX example primary RX example secondary RX example secondary RX example tertiary RX example

methyl RX example primary RX example secondary RX example secondary RX example tertiary RX example ucleophilic Substitution & Elimination hemistry 1 eginning patterns to knowfor S and E eactions - horizontal and vertical templates for practice Example 1 - two possible perspectives (deuterium and tritium

More information

AP Chemistry Chapter 22 - Organic and Biological Molecules

AP Chemistry Chapter 22 - Organic and Biological Molecules AP Chemistry Chapter - Organic and Biological Molecules.1 Alkanes: Saturated Hydrocarbons A. Straight-chain Hydrocarbons 1. Straight-chain alkanes have the formula C n H n+. Carbons are sp hybridized The

More information

ALKENES AND ALKYNES REACTIONS

ALKENES AND ALKYNES REACTIONS A STUDENT SHULD BE ABLE T: ALKENES AND ALKYNES REACTINS 1. Given the starting materials and reaction conditions, predict the products of the following reactions of alkenes and alkynes. Regioselective Markovnikov

More information

Introduction to Organic Chemistry Syllabus Day 1: Session 1 (evening session):

Introduction to Organic Chemistry Syllabus Day 1: Session 1 (evening session): Introduction to Organic Chemistry Syllabus Day 1: Session 1 (evening session): 1. Introduction to Organic Chemistry: 2. General discussion about what is chemistry? 3. What is organic chemistry? 4. What

More information

12. Alcohols and Phenols. Based on McMurry s Organic Chemistry, 6 th edition

12. Alcohols and Phenols. Based on McMurry s Organic Chemistry, 6 th edition 12. Alcohols and Phenols Based on McMurry s Organic Chemistry, 6 th edition Alcohols and Phenols Alcohols contain an OH group connected to a saturated C (sp 3 ) They are important solvents and synthesis

More information

Organic Chemistry II with Dr Roche

Organic Chemistry II with Dr Roche Organic Chemistry II with Dr Roche Lecture Notes Email http://roche.camden.rutgers.edu alroche@camden.rutgers.edu Office SCI-311 Labs SCI 328/309/319 Office Phone 856-225-6166 Text (a) Organic Chemistry

More information

Chapter 15 Radical Reactions. Radicals are reactive species with a single unpaired electron, formed by

Chapter 15 Radical Reactions. Radicals are reactive species with a single unpaired electron, formed by Chapter 15 Radical Reactions Radicals are reactive species with a single unpaired electron, formed by homolysis of a covalent bond; a radical contains an atom that does not have an octet of electrons,

More information

Lecture Notes Chem 51B S. King. Chapter 18 Electrophilic Aromatic Substitution

Lecture Notes Chem 51B S. King. Chapter 18 Electrophilic Aromatic Substitution Lecture otes Chem 51B S. King Chapter 18 Electrophilic Aromatic Substitution I. Electrophilic Aromatic Substitution The most characteristic reaction of aromatic compounds is electrophilic aromatic substitution,

More information

Chemistry 222--Spring Third Problem Set Due 5/1/02 H H HO OH. H Ether C H

Chemistry 222--Spring Third Problem Set Due 5/1/02 H H HO OH. H Ether C H hemistry 222--Spring 2002--Third Problem Set Due 5/1/02 nswers Part. For the following reactions, give the predominant product. learly show stereochemistry when appropriate (that is, draw a structure that

More information

Chapter 17 Alcohols and Phenols

Chapter 17 Alcohols and Phenols John E. McMurry http://www.cengage.com/chemistry/mcmurry Chapter 17 Alcohols and Phenols Alcohols and Phenols Alcohols contain an OH group connected to a saturated C (sp 3 ) They are important solvents

More information

Chapter 3: Structure and Nomenclature of Organic Compounds Focus on Alkanes

Chapter 3: Structure and Nomenclature of Organic Compounds Focus on Alkanes hapter 3: Structure and Nomenclature of rganic ompounds Focus on Alkanes rganic molecules are composed of one or more functional groups attached to one or more hydrocarbon groups (alkyl or groups) I. Functional

More information

Organic Chemistry II / CHEM 252 Chapter 16 Aldehydes and Ketones I. Nucleophilic Addition to the Carbonyl Group

Organic Chemistry II / CHEM 252 Chapter 16 Aldehydes and Ketones I. Nucleophilic Addition to the Carbonyl Group Organic Chemistry II / CHEM 252 Chapter 16 Aldehydes and Ketones I. Nucleophilic Addition to the Carbonyl Group Bela Torok Department of Chemistry University of Massachusetts Boston Boston, MA 1 Nomenclature

More information

Learning Guide for Chapter 13 - Alkynes

Learning Guide for Chapter 13 - Alkynes Learning Guide for Chapter 3 - Alkynes I. Introduction to Alkynes - p II. tural ccurrence and Uses of Alkynes - p 5 III. Physical Properties of Alkynes - p 7 IV. Spectroscopy of Alkynes - p 7 V. Nomenclature

More information

SUMMARY OF ALKENE REACTIONS

SUMMARY OF ALKENE REACTIONS SUMMARY F ALKENE REACTINS Alkenes are primarily prepared by elimination reactions of molecules that contain good leaving groups attached to sp 3 carbons. Examples of such reactions are dehydrohalogenations

More information

The Chemistry of Alcohols and Thiols

The Chemistry of Alcohols and Thiols 0 0 The Chemistry of Alcohols and Thiols This chapter focuses on the reactions of alcohols and thiols. Like alkyl halides, alcohols undergo substitution and elimination reactions. owever, unlike alkyl

More information

Chapter 10 Introduction to Organic Chemistry: Alkanes. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition

Chapter 10 Introduction to Organic Chemistry: Alkanes. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition 1 hapter 10 Introduction to Organic hemistry: Alkanes Organic hemistry and Organic ompounds 2 An organic compound is a compound made from carbon atoms has one or more atoms has many atoms may also contain

More information

Class XII Chemistry Chapter: Alcohols, Phenols And Ethers

Class XII Chemistry Chapter: Alcohols, Phenols And Ethers 1 Class XII Chemistry Chapter: Alcohols, Phenols And Ethers Top concepts: 1. Structure of alcohols, phenols and ethers: 2. Preparation of alcohols: 3. Preparation of phenols: 2 4. Physical properties of

More information

Chapter 18. Reactions of Aldehydes and Ketones

Chapter 18. Reactions of Aldehydes and Ketones hapter 18. Reactions of 1 Aldehydes and Ketones Reaction of a nucleophile with an aldehyde or ketone gives an alkoxide, and subsequent hydrolysis leads to an alcohol. This chapter will define differences

More information

Organic Chemistry. Hydrocarbons. Introduction to Organic Molecules. The simplest organic molecules containing only carbon and hydrogen atoms

Organic Chemistry. Hydrocarbons. Introduction to Organic Molecules. The simplest organic molecules containing only carbon and hydrogen atoms Introduction to Organic Molecules Organic Chemistry: (1828) Friedrich Wohler first synthesized an organic compound from an inorganic source leading to the birth of Organic Chemistry. Organic chemistry

More information

Carbocations are electrophiles, and can therefore be useful reagents for forming new C-C bonds in EAS processes.

Carbocations are electrophiles, and can therefore be useful reagents for forming new C-C bonds in EAS processes. 1 (Continuation of Chapter 17 ) VIII. Friedel-Crafts Alkylation Carbocations are electrophiles, and can therefore be useful reagents for forming new C-C bonds in EAS processes. Friedal and Craft demonstrated

More information

Organic Chemistry Questions

Organic Chemistry Questions Organic Chemistry Questions 1 Molecules of 1-propanol and 2-propanol have different (1) percentage compositions (2) molecular masses (3) molecular formulas (4) structural formulas 2 Which compound is an

More information

Reaction 2. Radical addition of hydrogen bromide (HBr) to alkenes. (NOT COVERED THIS TIME)

Reaction 2. Radical addition of hydrogen bromide (HBr) to alkenes. (NOT COVERED THIS TIME) http://courses.chem.psu.edu/chem38/reactions/reactions.html Reaction 1. Electrophilic addition of hydrogen halides (HX) to alkenes. HCl, HBr in ether KI + H 3 PO 4 room temperature electrophilic addition

More information

The study of the structure and chemistry of stereoisomers is called stereochemistry

The study of the structure and chemistry of stereoisomers is called stereochemistry Structure and Properties of rganic Molecules Reading: Wade chapter 2, sections 2-7- 2-14 Study Problems: 2-35, 2-37, 2-39, 2-40, 2-41, 2-42, Key Concepts and Skills: Identify constitutional isomers and

More information

Carboxylic Acids When a carbonyl carbon also bears a hydroxyl group, then these compounds are appreciably acidic, and are called carboxylic acids.

Carboxylic Acids When a carbonyl carbon also bears a hydroxyl group, then these compounds are appreciably acidic, and are called carboxylic acids. Carboxylic Acids When a carbonyl carbon also bears a hydroxyl group, then these compounds are appreciably acidic, and are called carboxylic acids. R Carboxylic acids are classified according to the substituent

More information

Hydrocarbon Frameworks. Alkanes

Hydrocarbon Frameworks. Alkanes Hydrocarbon Frameworks. Alkanes SUMMARY Section 2.1 Section 2.2 Section 2.3 The classes of hydrocarbons are alkanes, alkenes, alkynes, and arenes. Alkanes are hydrocarbons in which all of the bonds are

More information

Substituted Alkanes. Alcohol Amine Ether Thiol

Substituted Alkanes. Alcohol Amine Ether Thiol Substituted Alkanes While alkanes have very few reactions that occur, combustion and some radical reactions, substituted alkanes display a variety of reactions and properties X ften the amount of information

More information

Reactions of Aromatic Compounds

Reactions of Aromatic Compounds Reactions of Aromatic Compounds Aromatic compounds are stabilized by this aromatic stabilization energy Due to this stabilization, normal S N 2 reactions observed with alkanes do not occur with aromatic

More information

ORGANIC CHEMISTRY I PRACTICE EXERCISE Elimination Reactions and Alkene Synthesis

ORGANIC CHEMISTRY I PRACTICE EXERCISE Elimination Reactions and Alkene Synthesis RGANIC CEMISTRY I PRACTICE EXERCISE Elimination Reactions and Alkene Synthesis ) ne of the products that results when -bromo-,-dimethylcyclopentane is heated in ethanol is shown below. Give a mechanism

More information

Monday, September 10th

Monday, September 10th Monday, September 10th Review Chapter 11 iclicker Quiz #1 Chapter 12 Chapter 13(maybe) Group assignment Keep checking the class webpage at www.bhsu.edu/danasunskis. Go to the course tab then CHEM107 Lecture

More information

Chapter 11 Unsaturated Hydrocarbons Alkenes and Alkynes

Chapter 11 Unsaturated Hydrocarbons Alkenes and Alkynes 1 Chapter 11 Unsaturated ydrocarbons Alkenes and Alkynes Saturated ydrocarbons 2 Saturated hydrocarbons have the maximum number of hydrogen atoms attached to each carbon atom are alkanes and cycloalkanes

More information

(b) (1S,2S)-2-methylcyclohexanecarboxylic acid. (b) CH 3 CH 2 CHCN CH 2 CH 3. (d) 2-ethylbutanenitrile

(b) (1S,2S)-2-methylcyclohexanecarboxylic acid. (b) CH 3 CH 2 CHCN CH 2 CH 3. (d) 2-ethylbutanenitrile hem 226 Problem Set #10 Fundamentals of rganic hemistry, 4 th edition, John McMurry. hapter 10 1. Give IUPA names for compounds - (e). (c) 3 3 2 3-methylbutanoic acid Br 3 2 2 4-bromopentanoic acid 3 2

More information

Double Bonds. Hydration Rxns. Hydrogenation Rxns. Halogenation. Formation of epoxides. Syn addition of 2 OH. Ozonolysis

Double Bonds. Hydration Rxns. Hydrogenation Rxns. Halogenation. Formation of epoxides. Syn addition of 2 OH. Ozonolysis Double Bonds What do we do with double bonds? We do addition reactions. In an addition reaction, something is added to both carbons involved in a double bond (or not involved in the double bond, in the

More information

4/18/2011. 9.8 Substituent Effects in Electrophilic Substitutions. Substituent Effects in Electrophilic Substitutions

4/18/2011. 9.8 Substituent Effects in Electrophilic Substitutions. Substituent Effects in Electrophilic Substitutions 9.8 Substituent effects in the electrophilic substitution of an aromatic ring Substituents affect the reactivity of the aromatic ring Some substituents activate the ring, making it more reactive than benzene

More information

Boston University Dresden Science Program ORGANIC CHEMISTRY CAS CH 203 Lecture

Boston University Dresden Science Program ORGANIC CHEMISTRY CAS CH 203 Lecture Boston University Dresden Science Program ORGANIC CHEMISTRY CAS CH 203 Lecture Instructor: Professor Wolf D. Habicher, Professor Claus Rüger Meeting Times Lectures: twice a week at 90 minutes each Discussions:

More information

Chapter 10. Conjugation in Alkadienes and Allylic Systems. Class Notes. B. The allyl group is both a common name and an accepted IUPAC name

Chapter 10. Conjugation in Alkadienes and Allylic Systems. Class Notes. B. The allyl group is both a common name and an accepted IUPAC name Chapter 10 Conjugation in Alkadienes and Allylic Systems Chapter 10 suggested problems: I. The allyl group Class Notes A. B. The allyl group is both a common name and an accepted IUPAC name 1. Allyl alcohol

More information

Advanced Organic Chemistry

Advanced Organic Chemistry Advanced Organic Chemistry THIRD EDITION Part A: Structure and Mechanisms FRANCIS A. CAREY and RICHARD J. SUNDBERG University of Virginia Charlottesville, Virginia PLENUM PRESS NEW YORK AND LONDON Contents

More information

Chapter 11. Free Radical Reactions

Chapter 11. Free Radical Reactions hapter 11 Free Radical Reactions A free radical is a species containing one or more unpaired electrons Free radicals are electron-deficient species, but they are usually uncharged, so their chemistry is

More information

Alkanes. Chapter 1.1

Alkanes. Chapter 1.1 Alkanes Chapter 1.1 Organic Chemistry The study of carbon-containing compounds and their properties What s so special about carbon? Carbon has 4 bonding electrons. Thus, it can form 4 strong covalent bonds

More information

Chapter 6. Alkenes: Structure and Stability

Chapter 6. Alkenes: Structure and Stability hapter 6. Alkenes: Structure and Stability Steric Acid (saturated fatty acid) Linoleic Acid (unsaturated fatty acid) Degrees of unsaturation saturated hydrocarbon n 2n2 cycloalkane (1 ring) n 2n alkene

More information

Benzene Benzene is best represented as a resonance hybrid:

Benzene Benzene is best represented as a resonance hybrid: Electrophilic Aromatic Substitution (EAS) is a substitution reaction usually involving the benzene ring; more specifically it is a reaction in which the hydrogen atom of an aromatic ring is replaced as

More information

Topic: Intermolecular forces. 7. Which compound would you expect to have the lowest boiling point? A) NH 2 B) NH 2

Topic: Intermolecular forces. 7. Which compound would you expect to have the lowest boiling point? A) NH 2 B) NH 2 SS2009-08-24 MULTIPLE CICE QUESTIS Part 2: unktionella grp intermolekylära krafter (Answers on pages 17-18) Topic: Intermolecular forces 1. Which compound would you expect to have the lowest boiling point?

More information

Chapter 10 Introduction to Organic Chemistry: Alkanes

Chapter 10 Introduction to Organic Chemistry: Alkanes hapter 10 Introduction to Organic hemistry: Alkanes 1 Organic hemistry An organic compound is a compound made from carbon atoms has one or more atoms has many atoms may also contain O, S, N, and halogens

More information

It does not react N.R.

It does not react N.R. Benzene versus yclohexene versus yclohexadiene 1 l l cyclohexene l l cyclohexadiene l Expect this to react similarly "cyclohexatriene" It does not react l N.R. benzene Benzene is resonance stabilized,

More information

CHEM 322 Organic Chemistry II - Professor Kathleen V. Kilway

CHEM 322 Organic Chemistry II - Professor Kathleen V. Kilway CHEM 322 Organic Chemistry II - Professor Kathleen V. Kilway "Organic Chemistry" by Maitland Jones, 4th edition Chapter 12 Homework: 1, 2, 4, 5, 6, 7, 15, 16, 17, 19, 21, 24, 26, 28, 29, 30, 38, 39, 44,

More information

Worksheet Addition reactions

Worksheet Addition reactions Worksheet Addition reactions The presence of electrons in alkenes allows addition reactions to take place. In general: In each case, the bond is broken and the e - are used to form a new bond in the product

More information

Chapter 11 Organic Compounds: Alkanes

Chapter 11 Organic Compounds: Alkanes Spencer L. Seager Michael R. Slabaugh www.cengage.com/chemistry/seager Chapter 11 Organic Compounds: Alkanes Jennifer P. Harris ORGANIC COMPOUNDS In 1828, Friedrich Wöhler first synthesized an organic

More information

13.1 Alcohols and Phenols. Nomenclature. Nomenclature. Nomenclature. Alcohols possess a hydroxyl group ( OH). Hydroxyl groups in natural compounds.

13.1 Alcohols and Phenols. Nomenclature. Nomenclature. Nomenclature. Alcohols possess a hydroxyl group ( OH). Hydroxyl groups in natural compounds. 13.1 Alcohols and Phenols Alcohols possess a hydroxyl group ( OH). 13.1 Alcohols and Phenols Hydroxyl groups in natural compounds. Hydroxyl groups are extremely common in natural compounds. 13-1 13-2 13.1

More information

Q.1 Carbonyl compounds are formed by oxidation of alcohols;

Q.1 Carbonyl compounds are formed by oxidation of alcohols; arbonyl compounds 814 1 ARBYL MPUDS - Aldehydes and Ketones Q.1 arbonyl compounds are formed by oxidation of alcohols; a) Which type of alcohol is oxidised to an aldehyde? b) Which type of alcohol is oxidised

More information

CHEM 203 Exam 1. KEY Name Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.

CHEM 203 Exam 1. KEY Name Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. CHEM 203 Exam 1 KEY Name Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. _D C 1. Which of the following elements is a large percentage of both

More information

Chapter 11 Unsaturated Hydrocarbons. Saturated Hydrocarbons. Unsaturated Hydrocarbons Alkenes and Alkynes

Chapter 11 Unsaturated Hydrocarbons. Saturated Hydrocarbons. Unsaturated Hydrocarbons Alkenes and Alkynes 1 hapter 11 Unsaturated ydrocarbons 11.1 Alkenes and Alkynes opyright 2009 by Pearson Education, Inc. 1 2 Saturated ydrocarbons Saturated hydrocarbons have the maximum number of hydrogen atoms attached

More information

Chem 401 Lab Exercise #5 Nomenclature Worksheet for Alkanes and Cycloalkanes

Chem 401 Lab Exercise #5 Nomenclature Worksheet for Alkanes and Cycloalkanes hem 401 Lab Exercise #5 Nomenclature Worksheet for Alkanes and ycloalkanes Structure and Nomenclature of Alkanes Alkanes are saturated hydrocarbons; that is, they contain only and which are bonded solely

More information

ALKENES AND ALKYNES REACTIONS A STUDENT WHO HAS MASTERED THE MATERIAL IN THIS SECTION SHOULD BE ABLE TO:

ALKENES AND ALKYNES REACTIONS A STUDENT WHO HAS MASTERED THE MATERIAL IN THIS SECTION SHOULD BE ABLE TO: ALKENES AND ALKYNES REACTINS A STUDENT W AS MASTERED TE MATERIAL IN TIS SECTIN SULD BE ABLE T: 1. Given the starting materials and reaction conditions, predict the products of the following reactions of

More information

Radical and Cation Stabilities Radical vs cation stabilities

Radical and Cation Stabilities Radical vs cation stabilities Mass Spectrometry and Free Radicals MS recap Positive mode of Electron Ionization / ESI MS sees charged species (M+, M+), but does not see uncharged (R ) Radical and Cation Stabilities Radical vs cation

More information

Chapter 12 Electrophilic and Nucleophilic Aromatic Substitution

Chapter 12 Electrophilic and Nucleophilic Aromatic Substitution Chapter 12 Electrophilic and Nucleophilic Aromatic Substitution CHAPTER 12 Electrophilic and Nucleophilic Aromatic Substitution Aromatic compounds may undergo substitution reactions. Electrophilic aromatic

More information

KOT 222 ORGANIC CHEMISTRY II CHAPTER 17. REACTIONS of AROMATIC COMPOUNDS

KOT 222 ORGANIC CHEMISTRY II CHAPTER 17. REACTIONS of AROMATIC COMPOUNDS KOT 222 ORGANIC CEMISTRY II CAPTER 17 REACTIONS of AROMATIC COMPOUNDS 1 Electrophilic Aromatic Substitution Substitution of an electrophile for a proton on the aromatic ring. benzene s pi electrons are

More information

partial positive an acid is a hydrogen ion donor, or proton donor base is a hydrogen ion acceptor, or proton acceptor acidic protons acid base

partial positive an acid is a hydrogen ion donor, or proton donor base is a hydrogen ion acceptor, or proton acceptor acidic protons acid base INTRDUCTIN T INIC MECANISMS PART I: FUNDAMENTALS F BRNSTED-LWRY ACID-BASE CEMISTRY YDRGEN ATMS AND PRTNS IN RGANIC MLECULES - A hydrogen atom that has lost its only electron is sometimes referred to as

More information

Last Time: Alkanes (C n H 2n+2 ) Last Time: Organic Compounds. Last Time: Intermolecular Forces- BP Increases w/ Increasing Size

Last Time: Alkanes (C n H 2n+2 ) Last Time: Organic Compounds. Last Time: Intermolecular Forces- BP Increases w/ Increasing Size Announcements & Agenda (0/02/07) Welcome Visitors! Please make yourselves comfortable; we will start with a quiz Mid-term grades are only based on lecture I will give you detailed grade sheets on Monday

More information

1 Lecture 5 Resonance 1. Lone pair next to empty 2p orbital

1 Lecture 5 Resonance 1. Lone pair next to empty 2p orbital 1 Lecture 5 esonance 1. Lone pair next to empty 2p orbital sp 2 + is more common sp + is less common + needs electrons, has to overlap with a. an adjacent 2p lone pair with electrons b. an adjacent pi

More information

Benzene benzene aromatic hydrocarbons aromatic not not

Benzene benzene aromatic hydrocarbons aromatic not not Benzene 1 NT 87 90 ompound 87 has the formula 6 6, is known as benzene, and it is a hydrocarbon derived from petroleum distillates. Benzene is the parent compound for a class of compounds known as aromatic

More information

Where R = alkyl group, Nu = nucleophile and L = leaving group.

Where R = alkyl group, Nu = nucleophile and L = leaving group. Organic Chemistry (CEM311) Fall 2005 Dr. Robert F. Dias 9. SUBSTITUTIONS: S N 1, S N 2 2 basic kinds of substitution reactions: S N 2 = Substitution Nucleophillic Bimolecular S N 1 = Substitution Nuclophillic

More information

Chapter 2 - Families of Carbon Compounds

Chapter 2 - Families of Carbon Compounds Andrew Rosen Chapter 2 - Families of Carbon Compounds 2.1 - Hydrocarbons: Representative Alkanes, Alkenes, Alkynes, and Aromatic Compounds - Hydrocarbons are compounds that contain only hydrogen and carbon

More information

Chapter: Introduction to Organic Chemistry: Alkanes

Chapter: Introduction to Organic Chemistry: Alkanes Chapter: Introduction to Organic Chemistry: Alkanes Organic Chemistry An organic compound is a compound made from carbon atoms. has one or more C atoms. has many H atoms. may also contain O, S, N, and

More information