# Chapter 7 Substitution Reactions

Size: px
Start display at page:

## Transcription

1 Chapter 7 Substitution Reactions Review of Concepts Fill in the blanks below. To verify that your answers are correct, look in your textbook at the end of Chapter 7. Each of the sentences below appears verbatim in the section entitled Review of Concepts and Vocabulary. Substitution reactions exchange one for another. Evidence for the concerted mechanism, called S 2, includes the observation of a -order rate equation. The reaction proceeds with of configuration. S 2 reactions are said to be because the configuration of the product is determined by the configuration of the substrate. Evidence for the stepwise mechanism, called S 1, includes the observation of a -order rate equation. The step of an S 1 process is the rate-determining step. An S 1 reaction is a stepwise process with a first-order rate equation. There are four factors that impact the competition between the S 2 mechanism and S 1: 1) the, 2) the, 3) the, and 4) the. solvents favor S 2. Review of Skills Follow the instructions below. To verify that your answers are correct, look in your textbook at the end of Chapter 7. The answers appear in the section entitled SkillBuilder Review. SkillBuilder 7.1 Drawing the Curved Arrows of a Substitution Reaction A CCERTED MECAISM DRAW CURVED ARRWS, SWIG UCLEPILIC ATTACK ACCMPAIED BY SIMULTAEUS LSS F A LEAVIG GRUP A STEPWISE MECAISM DRAW A CURVED ARRW SWIG TE LSS F TE LEAVIG GRUP T FRM A CARBCATI ITERMEDIATE, FLLWED BY ATER CURVED ARRW SWIG TE UCLEPILIC ATTACK uc - LG - LG LG uc uc LG uc SkillBuilder 7.2 Drawing the Product of an S 2 Process DRAW TE MAJR PRDUCT F TE FLLWIG REACTI

2 CAPTER SkillBuilder 7.3 Drawing the Transition State of an S 2 Process DRAW TE TRASITI STATE F TE FLLWIG REACTI as S TRASITI STATE SkillBuilder 7.4 Drawing the Carbocation Intermediate of an S 1 Process DRAW TE CARBCATI TAT WULD BE FRMED IF A CLRIDE I IS EXPELLED FRM TE FLLWIG CMPUD - SkillBuilder 7.5 Drawing the Products of an S 1 Process PREDICT TE PRDUCTS F TE FLLWIG S 1 REACTI ac SkillBuilder 7.6 Drawing the Complete chanism of an S 1 Process IDETIFY TE TW CRE STEPS AD TREE PSSIBLE ADDITIAL STEPS F A S 1 PRCESS TW CRE STEPS TREE PSSIBLE ADDITIAL STEPS SkillBuilder 7.7 Drawing the Complete chanism of an S 2 Process IDETIFY TE E CRE STEP (CCERTED) AD TW PSSIBLE ADDITIAL STEPS F A S 2 PRCESS CRE STEP TW PSSIBLE ADDITIAL STEPS

3 116 CAPTER 7 SkillBuilder 7.8 Determining whether a Reaction Proceeds via an S 1 chanism or an S 2 chanism FILL I TE TABLE BELW, SWIG TE FEATURES TAT FAVR S 2 R S 1 REACTIS S 2 S 1 SUBSTRATE UC LG SLVET SkillBuilder 7.9 Identifying the Reagents ecessary for a Substitution Reaction IDETIFY TE REAGETS ECESSARY T ACIEVE TE FLLWIG TRASFRMATI 1) C 2) Review of Reactions Follow the instructions below. To verify that your answers are correct, look in your textbook at the end of Chapter 7. The answers appear in the section entitled Review of Reactions. S 2 DRAW TE CURVED ARRWS TAT SW TE FLW F ELECTR DESITY DURIG TE FLLWIG S 2 REACTI LG uc uc LG S 1 DRAW TE CURVED ARRWS TAT SW TE FLW F ELECTR DESITY DURIG TE FLLWIG S 1 REACTI LG - LG uc uc

4 CAPTER Solutions chloro-4-ethylheptane 1-bromo-1-methylcyclohexane 4,4-dibromo-1-chloropentane d) (S)-5-fluoro-2,2-dimethylhexane 7.2. S S I I 7.3. I 7.4.

5 118 CAPTER the rate of the reaction is tripled. the rate of the reaction is doubled. the rate of the reaction will be six times faster S F 3 C 2 3 S 1 The reaction does proceed with inversion of configuration. owever, the Cahn-Ingold- Prelog system for assigning a stereodescriptor (R or S) is based on a prioritization scheme. Specifically, the four groups connected to a chirality center are ranked (one through four). In the reactant (above left), the highest priority group is the leaving group (bromide) which is then replaced by a group that does not receive the highest priority. In the product, the fluorine atom has been promoted to the highest priority as a result of the reaction, and as such, the prioritization scheme has changed. In this way, the stereodescriptor (S) remains unchanged, despite the fact that chirality center undergoes inversion. 2 S 1 F C 3 3 4

6 CAPTER d) δ δ Being formed Being broken This step is favorable (downhill in energy) because ring strain is alleviated when the three-membered ring is opened C 3 R S R C 3 C 3 icotine

7 120 CAPTER 7 3 C 3 C C 3 R S R 3 C C 3 C 3 choline The rate of the reaction will be doubled, because the change in concentration of sodium chloride will not affect the rate. The rate of the reaction will remain the same, because the change in concentration of sodium chloride will not affect the rate Draw the carbocation intermediate generated by each of the following substrates in an S 1 reaction: ( ( ( (d) The first compound will generate a tertiary carbocation, while the second compound will generate a tertiary benzylic carbocation that is resonance stabilized. The second compound leads to a more stable carbocation, so that compound will lose its leaving group more rapidly than the first compound S a S d)

8 CAPTER S S Diastereomers o Yes o d) Yes e) Yes f) o o Yes Yes d) Yes e) o f) o g) o h) Yes i) o j) o k) Yes l) o o Yes Yes d) o e) o f) o 7.21.

9 122 CAPTER 7 d) Et Et Et Et e) f) g) S S h) Et Et Et Et

10 CAPTER LG uc Attack - d) - C LG rearr. uc Attack - e) - LG uc Attack - f) - C LG rearr. uc Attack - g) -LG uc Attack h) - LG uc Attack - Problem 7.20c and 7.20h exhibit the same pattern. Both problems are characterized by three mechanistic steps: 1) loss of a leaving group, 2) nucleophilic attack, and 3) proton transfer The chirality center at C2 is lost when the leaving group leaves to form a carbocation with trigonal planar geometry. The chirality center at C3 is lost during the hydride shift in the following step. nce again, the chirality center is converted into a trigonal planar sp 2 hybridized center (which is no longer a chirality center).

11 124 CAPTER Et Et Et d) S 1 S 2 either d) S 1 e) Both f) either g) Both

12 CAPTER S 1 S 2 S 2 d) S 2 e) S Ts I 2 F Ts I 2 F S 1 S 2 S 1 d) S 2 e) S 1 f) S 2 g) S 2 h) S Acetone is a polar aprotic solvent and will favor S 2 by raising the energy of the nucleophile, giving a smaller E a I S 1 MPA S 2 S 1 Racemic d) Ts ac DMF C S 2

13 126 CAPTER 7 I 2 S 1 e) Racemic f) ac DMS C S o. Preparation of this amine via the Gabriel synthesis would require the use of a tertiary alkyl halide, which will not undergo an S 2 process ( I a ( as S ( I I (d) DMS 1) Ts, pyridine (e) DMS (f) 2) a, DMS (g) I (h) 2 (i) 1) Ts, pyridine 2) ac C ) Ts, pyridine S 2) ai, DMS 3) as, DMS (R)- (R)- 2-butanol 2-butanethiol

14 CAPTER melphalan uc 2 uc 2 uc uc 2 uc uc Systematic ame = 2-chloropropane Common ame = isopropyl chloride Systematic ame = 2-bromo-2-methylpropane Common ame = tert-butyl bromide Systematic ame = 1-iodopropane Common ame = propyl iodide d) Systematic ame = 2-chlorobutane Common ame = propyl iodide d) Systematic ame = (R)-2-bromobutane Common ame = (R)-sec-butyl bromide e) Systematic ame = 1-chloro-2,2-dimethylpropane Common ame = neopentyl chloride f) Systematic ame = chlorocyclohexane Common ame = cyclohexyl chloride

15 128 CAPTER Increasing reactivity (S 2) secondary primary primary more sterically hindered primary less sterically hindered I secondary tertiary d) better leaving group o. Preparation of this compound via the process above would require the use of a tertiary alkyl halide, which will not undergo an S 2 process as sodium hydroxide methoxide dissolved in DMS tertiary primary primary tertiary Ts allylic d) better leaving group

16 CAPTER The rate of the reaction is doubled. The rate of the reaction is doubled The rate of the reaction is doubled The rate of the reaction will remain the same aprotic protic aprotic d) protic e) protic R C R The reaction is an S 2 process, and it does proceed with inversion of configuration. owever, the prioritization scheme changes when bromide (#1) is replaced with a cyano group (#2). As a result, the Cahn-Ingold-Prelog system assigns the same configuration to the reactant and the product δ δ Iodide functions as a nucleophile and attacks (S)-2-iodopentane, displacing iodide as a leaving group. The reaction is an S 2 process, and therefore proceeds via inversion of configuration. The product is (R)-2-iodopentane. The reaction continues until a racemic mixture is obtained.

17 130 CAPTER Racemic The chirality center is lost when the leaving group leaves to form a carbocation with trigonal planar geometry. The nucleophile can then attack either face of the planar carbocation, leading to a racemic mixture S S Racemic E Reaction coordinate Increasing stability secondary tertiary primary secondary

18 CAPTER Steps S S 2 Steps 2 3 Steps

19 132 CAPTER 7 d) Ts Et Et Et Et 4 Steps Et Et Ts a d) I ac DMS C Although the substrate is primary, it is still sterically hindered. As a result, S 2 reactions at neopentyl halides do not occur at an appreciable rate.

20 CAPTER The substrate is primary, and therefore, the reaction must proceed via an S 2 process. S 2 reactions are highly sensitive to the strength of the nucleophile, and the nucleophile (water) is a weak nucleophile. As a result, the reaction occurs slowly. ydroxide is a strong nucleophile, which favors the S 2 process a Ts 1) Ts, py 2) ac C d) as S e) a

21 134 CAPTER C d) S e) 2 f) 2 S S C S Et The second method is more efficient because the alkyl halide (methyl iodide) is not sterically hindered. The first method is not efficient because it employs a tertiary alkyl halide, and S 2 reactions do not occur at tertiary substrates ) Ts, pyridine 2) a a

22 CAPTER S S Rate = k as The rate would be slower. E d) Reaction coordinate e) δ S Et δ S 1 (tertiary substrate) Rate = k d) o. The rate is not dependent on the concentration or strength of the nucleophile. E e) Reaction coordinate

23 136 CAPTER S 2 C C Rate = k ac d) Yes. The reaction rate would double. E e) Reaction coordinate I

24 CAPTER I I This reaction occurs via an S 2 process. As such, the rate of the reaction is highly sensitive to the nature of the substrate. The reaction will be faster in this case, because the methyl ester is less sterically hindered than the ethyl ester Base Et Et Et Et When the leaving group leaves, the carbocation formed is resonance stabilized: Ts Resonance stabilized Iodide is a very good nucleophile (because it is polarizable), and it is also a very good leaving group (because it can stabilize the negative charge by spreading the charge over a large volume of space). As such, iodide will function as a nucleophile to displace the chloride ion. nce installed, the iodide group is a better leaving group than chloride, thereby increasing the rate of the reaction.

25 138 CAPTER

### ORGANIC CHEMISTRY I PRACTICE EXERCISE Sn1 and Sn2 Reactions

ORGANIC CEMISTRY I PRACTICE EXERCISE Sn1 and Sn2 Reactions 1) Which of the following best represents the carbon-chlorine bond of methyl chloride? d d - d - d d d d - d - I II III IV V 2) Provide a detailed,

### 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

### Chapter 11 Homework and practice questions Reactions of Alkyl Halides: Nucleophilic Substitutions and Eliminations

Chapter 11 Homework and practice questions Reactions of Alkyl Halides: Nucleophilic Substitutions and Eliminations SHORT ANSWER Exhibit 11-1 Circle your response in each set below. 1. Circle the least

### 2. Determine the product that would be formed from the S N 2 reaction of a. (R)-2-bromobutane and hydroxide ion (aprotic solvent) (S)-2-butanol

1. Define and understand the following terms. (I will go over these if you have questions, but will expect that you have attempted to understand them on your own.) a. yperconjugation b. Basicity c. Nucleophile

### CHEMICAL REACTIVITY AND MECHANISMS, AND SUBSTITUTION REACTIONS

EMIAL REATIVITY AND MEANISMS, AND SUBSTITUTION REATIONS A STUDENT SOULD BE ABLE TO: 1. Understand the concepts of: enthalpy, entropy, free energy, equilibrium and kinetics. Given a reaction coordinate

### Willem Elbers. October 9, 2015

S N 1 and S N 2 reactivity of 3 alkyl bromides Willem Elbers ctober 9, 2015 1 Abstract n this experiment, we investigate the relative reactivities of three alkyl bromides with increasing steric bulk. We

### SUBSTITUTION REACTION CHARACTERISTICS. Sn1: Substitution Nucleophilic, Unimolecular: Characteristics

SUBSTITUTION EATION AATEISTIS Sn2: Substitution cleophilic, Bimolecular: haracteristics 1) The 2 means Bimolecular (or 2 nd order) in the rate-determining (slow) step: rate = k [: - ] [-X] or rate = k

### 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

### 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,

### 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

### 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

### 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

### Writing a Correct Mechanism

Chapter 2 1) Balancing Equations Writing a Correct Mechanism 2) Using Arrows to show Electron Movement 3) Mechanisms in Acidic and Basic Media 4) Electron rich Species: Nucleophile or Base? 5) Trimolecular

### Nucleophilic Substitution and Elimination

Nucleophilic Substitution and Elimination What does the term "nucleophilic substitution" imply? A nucleophile is an the electron rich species that will react with an electron poor species A substitution

### 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

### 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

### 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

### RESONANCE, USING CURVED ARROWS AND ACID-BASE REACTIONS

RESONANCE, USING CURVED ARROWS AND ACID-BASE REACTIONS A STUDENT SHOULD BE ABLE TO: 1. Properly use curved arrows to draw resonance structures: the tail and the head of every arrow must be drawn in exactly

### 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

INTDUCTIN T LEWIS ACID-BASE CEMISTY DEINITINS Lewis acids and bases are defined in terms of electron pair transfers. A Lewis base is an electron pair donor, and a Lewis acid is an electron pair acceptor.

### So far we have mostly limited our good leaving groups to the very similar, stable halide anions, Cl -, Br - and I -.

Extending the - pectrum: Making Alcohols () into eactive and E eactants (Two Ways) o far we have mostly limited our good leaving groups to the very similar, stable halide anions, -, Br - and I -. 1 Base

### Carboxylic Acid Derivatives and Nitriles

Carboxylic Acid Derivatives and itriles Carboxylic Acid Derivatives: There are really only four things to worry about under this heading; acid chlorides, anhydrides, esters and amides. We ll start with

### SULFONATE AND INORGANIC ESTER DERIVATIVES OF ALCOHOLS

0. ULFNATE AND INRGANIC ETER DERIVATIVE F ALCL 44 R 2 C L CR 2 carbocation Lewis acid base association X (halide ion) 2 \$ R 2 C L CR 2 R R X C A C \$ alkyl halide R R alkene \$ \$ Brønsted acid base reaction

### 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

### Organic Chemistry II / CHEM 252 Chapter 20 Amines

Organic Chemistry II / CHEM 252 Chapter 20 Amines Bela Torok Department of Chemistry University of Massachusetts Boston Boston, MA 1 Nomenclature Nomenclature Primary amines are named in systematic (IUPAC)

### CHM220 Nucleophilic Substitution Lab. Studying S N 1 and S N 2 Reactions: Nucloephilic Substitution at Saturated Carbon*

CHM220 Nucleophilic Substitution Lab Studying S N 1 and S N 2 Reactions: Nucloephilic Substitution at Saturated Carbon* Purpose: To convert a primary alcohol to an alkyl bromide using an S N 2 reaction

### 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

### SN2 Ionic Substitution Reactions

SN2 Ionic Substitution Reactions Chem 14D Winter 2005 SN2 Ionic Substitution Reactions Substitution can occur in organic compounds that have an electronegative atom or group bonded to an sp 3 hybridized

### CHAPTER 11 Alcohol Reactivity

CHAPTER 11 Alcohol Reactivity 1 Summary Table Oxidation: Adding O, Losing H Chromic Acid (Cr(VI)) is a powerful oxidizing agent 4 Oxidation Mechanism When Aldehydes are formed by Cr(VI) in water, they

### CHEM 343 Principles of Organic Chemistry II Summer Instructor: Paul J. Bracher. Exam # 1. Tuesday, July 8 th, :00 9:15 a.m.

CHEM 343 Principles of rganic Chemistry II Summer 2014 Exam # 1 Solutions Key Page 1 of 7 CHEM 343 Principles of rganic Chemistry II Summer 2014 Instructor: Paul J. Bracher Exam # 1 Tuesday, July 8 th,

### Chemistry 232 Summer 2016 Quiz 2a

1 Chemistry 232 Summer 2016 Quiz 2a KEY Name: (Please print, surname first) ID: Do all questions. Time available: 20 min. Total available marks: 20. Score for this quiz: Answers written partially or completely

### 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

### 7: Reactions of Haloalkanes, Alcohols, and Amines. Nucleophilic Substitution

7: Reactions of Haloalkanes, Alcohols, and Amines. Nucleophilic Substitution Nucleophilic Substitution Reactions of Haloalkanes S N 1 versus S N 2 Mechanisms Haloalkane Structure and Reactivity Stereochemistry

### Avg. 16.4 / 25 Stnd. Dev. 8.2

QUIZ TREE Avg. 16.4 / 25 Stnd. Dev. 8.2 xidation of Alcohols with Chromium (VI): Jones xidation 2 Alcohols are oxidized by a solution of chromium trioxide in aqueous acetone (2), in the presence of an

### Chemistry 52 Final Exam. This exam has six questions, two cover pages, ten exam pages, and three scratch pages.

Chemistry 52 Final Exam Name: 10 March 2003 This exam has six questions, two cover pages, ten exam pages, and three scratch pages. Please check before beginning to make sure no questions or pages are missing.

### 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

### 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

### CHEM 211 CHAPTER 16 - Homework

CHEM 211 CHAPTER 16 - Homework SHORT ANSWER Consider the Friedel-Crafts alkylation reaction below to answer the following question(s): 1. Refer to the reaction above. Draw the structure of the electrophilic

### 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

### 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,

### 21.9 REDUCTION OF CARBOXYLIC ACID DERIVATIVES

10 APTER 1 TE EMITRY F ARBXYLI AID DERIVATIVE TUDY GUIDE LIK 1.5 Esters and ucleophiles 1.17 Give the structure of the product in the reaction of each of the following esters with isotopically labeled

### 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,

### PRACTICE PROBLEMS, CHAPTERS 1-3

PRATIE PRBLEMS, APTERS 1-3 (overed from h. 3: Alkane and Alkyl alide nomenclature only) 1. The atomic number of boron is 5. The correct electronic configuration of boron is: A. 1s 2 2s 3 B. 1s 2 2p 3.

### Experiment 6 Qualitative Tests for Alcohols, Alcohol Unknown, IR of Unknown

Experiment 6 Qualitative Tests for Alcohols, Alcohol Unknown, I of Unknown In this experiment you are going to do a series of tests in order to determine whether or not an alcohol is a primary (1 ), secondary

### 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

### 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

### Benzene does not undergo electrophilic addition. It undergoes electrophilic aromatic substitution maintaining the aromatic core

Substitution Reactions of Benzene and Its Derivatives Benzene does not undergo electrophilic addition It undergoes electrophilic aromatic substitution maintaining the aromatic core Electrophilic aromatic

### Everything You Need to Know About Mechanisms. First rule: Arrows are used to indicate movement of electrons

Everything You eed to Know About Mechanisms A) The orrect Use of Arrows to Indicate Electron Movement The ability to write an organic reaction mechanism properly is key to success in organic chemistry

### Electrophilic Aromatic Substitution Reactions

Electrophilic Aromatic Substitution Reactions, Course Notes Archive, 1 Electrophilic Aromatic Substitution Reactions An organic reaction in which an electrophile substitutes a hydrogen atom in an aromatic

### QOI 0809 SN. Name. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

QOI 0809 SN Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following best describes the carbon-chlorine bond of an alkyl chloride?

### 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

### REACTIONS OF AROMATIC COMPOUNDS

A STUDENT SHOULD BE ABLE TO: REACTIONS OF AROMATIC COMPOUNDS 1. Predict the product(s) of Electrophilic Aromatic Substitution (EAS), Nucleophilic Aromatic Substitution (S N Ar) and Elimination-Addition

### Chapter 16: Chemistry of Benzene: Electrophilic Aromatic Substitution. Let us look at bromination: δ+ δ Br Br FeBr 3 Br Br FeBr 3

Chapter 16: Chemistry of Benzene: lectrophilic Aromatic Substitution lectrophilic positively charged species searching for electron density Aromatic benzene ring with a high electron density Substitution

### 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

### 17.2 REACTIONS INVOLVING ALLYLIC AND BENZYLIC RADICALS

17. REACTINS INVLVING ALLYLIC AND BENZYLIC RADICALS 793 As Eq. 17. shows, the products derived from the reaction of water at the ring carbons are not formed. The reason is that these products are not aromatic

### Stereochemistry. In organic chemistry, subtle differences in spatial arrangements can give rise to prominent effects.

Stereochemistry This is study of the 3 dimensional arrangement in space of molecules. In organic chemistry, subtle differences in spatial arrangements can give rise to prominent effects. E.g. the isomers

### 2.7 Acids and Bases: The Brønsted-Lowry Definition. Acids and Bases: The Brønsted-Lowry Definition. Acids and Bases: The Brønsted-Lowry Definition

2.7 Acids and Bases: The Brønsted-Lowry Definition Two frequently used definitions of acidity The Brønsted-Lowry definition Lewis definition Brønsted-Lowry acid A substance that donates a hydrogen ion

### 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

### Lecture 8. Friedel-Crafts reaction: Mechanism: Carbocation is the reactive electrophile. AlCl4- picks up a proton.

New Section 3 Page 1 2:37 PM Friedel-Crafts reaction: Mechanism: Carbocation is the reactive electrophile. AlCl4- picks up a proton. Limitations come from the mechanism: Carbocationic intermediates prone

### Electrophilic Aromatic Substitution

Electrophilic Aromatic Substitution Electrophilic Aromatic Substitution: a reaction in which the hydrogen atom of an aromatic ring is replaced as a result of an electrophilic attack on the aromatic ring

### Experiment: Friedel-Crafts Alkylation of p- Xylene

Experiment: Friedel-Crafts Alkylation of p- Xylene INTODUCTION In this experiment, an alkyl group is substituted for a hydrogen atom located on an aromatic ring substrate using the Friedel-Crafts alkylation

### Chem 2425 Review Test 2

Name: Class: Date: Chem 2425 Review Test 2 Draw structures corresponding to each of the given names. 1. 2-phenyl-2-propanol 2. 2, 4, 6-trinitrophenol 3. tetrahydrofuran 4. allyl benzyl ether 5. diethyl

### 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

### Electrophilic Aromatic Substitution Part 1

Electrophilic Aromatic Substitution Part 1 Generic reaction: Optional reading: OCATSA Email instructor for access Introduction Fact: Alkenes undergo electrophilic addition Addition reaction: Increases

### Chapter 17: Reactions of Aromatic Compounds

Chapter 17: Reactions of Aromatic Compounds Electrophilic aromatic substitution (17-1) Most common (normal) reaction of aromatics HNO 3 H 2 SO 4 NO 2 + H2O 452 Similar to alkenes, benzene (aromatics) has

### 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

### Principles Of Drug Action 1, Spring 2005, Halogenated Hydrocarbons HALOGENATED HYDROCARBON STRUCTURE AND CHEMISTRY.

Principles f Drug Action 1, Spring 2005, alogenated ydrocarbons ALGENATED YDRCARBN STRUCTURE AND CEMISTRY I. Introduction Jack DeRuiter alogenated hydrocarbons are organic compounds consisting of C-C,

### Electrophilic Reactions on Aromatic Compounds Monosubstitution. Dr. Sapna Gupta

Electrophilic Reactions on Aromatic Compounds Monosubstitution Dr. Sapna Gupta Electrophilic Aromatic Substitution Arene (Ar-H) is the generic term for an aromatic hydrocarbon The aryl group (Ar) is derived

### Chapter 2 Polar Covalent Bonds; Acids and Bases

John E. McMurry http://www.cengage.com/chemistry/mcmurry Chapter 2 Polar Covalent Bonds; Acids and Bases Javier E. Horta, M.D., Ph.D. University of Massachusetts Lowell Polar Covalent Bonds: Electronegativity

### Q.1 Draw out some suitable structures which fit the molecular formula C 6 H 6

Aromatic compounds GE 1 BENZENE Structure Primary analysis revealed benzene had an... empirical formula of and a molecular formula of 6 6 Q.1 Draw out some suitable structures which fit the molecular formula

### CHE Organic Chemistry Exam 1 January 31, 1996

E 232-001 rganic hemistry Exam 1 January 31, 1996 Name KEY Student ID No. Before you begin this exam: First: You are allowed to have a calculator and a simple model set at your seat. Please put away all

### Arene(Ar-H) is the generic term for an aromatic hydrocarbon

4.8 Electrophilic Aromatic Substitution Arene(Ar-H) is the generic term for an aromatic hydrocarbon The aryl group (Ar) is derived by removal of a hydrogen atom from an arene Aromatic compounds undergo

### 508 CHAPTER TWELVE Reactions of Arenes: Electrophilic Aromatic Substitution O O BF 3. Acetic anhydride H H

508 CAPTR TWLV Reactions of s: lectrophilic Aromatic Substitution C3 CCC 3 BF 3 CC C 3 C 3 Furan Acetic anhydride 2-Acetylfuran (75 92%) Acetic acid The regioselectivity of substitution in furan is explained

### 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

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,

### Synthesis of Isopentyl Acetate

Experiment 8 Synthesis of Isopentyl Acetate Objectives To prepare isopentyl acetate from isopentyl alcohol and acetic acid by the Fischer esterification reaction. Introduction Esters are derivatives of

### 3.4 BRØNSTED LOWRY ACIDS AND BASES

96 CAPTER 3 ACIDS AND BASES. TE CURVED-ARROW NOTATION and that the unshared electron pair (and negative charge) is shared equally by the two terminal carbons. C L C A C 1 allyl anion (c) Using the curved-arrow

### 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

### 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

### Substitution and Elimination Reactions. 7.1. Definitions. In an acid base reaction such as CH 3 CO 2 H + NH 3 CH 3 CO 2 + NH 4

Substitution and Elimination Reactions. 7.1. Definitions. In an acid base reaction such as CH 3 CO 2 H + NH 3 CH 3 CO 2 + NH 4 +, the N acts as a nucleophile (Greek for loving the nucleus), the H acts

### Name. Department of Chemistry and Biochemistry SUNY/Oneonta. Chem 322 - Organic Chemistry II Examination #2 - March 14, 2005 ANSWERS

Name INSTRUTINS --- Department of hemistry and Biochemistry SUNY/neonta hem 322 - rganic hemistry II Examination #2 - March 14, 2005 ANSWERS This examination has two parts. Part I is in multiple choice

### (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

### The main culprit is a small compound called ethylene

Alkenes: Structure and Preparation via Elimination Reactions DID YU EVER WNDER why fruit ripens more quickly in a paper bag The main culprit is a small compound called ethylene ( 2 C C 2 ). At room temperature

### Chemistry 2030 Survey of Organic Chemistry Fall Semester 2013 Dr. Rainer Glaser

Chemistry 2030 Survey of Organic Chemistry Fall Semester 2013 Dr. Rainer Glaser Examination #2 Arenes, Electrophilic Aromatic Substitution, Stereochemistry, and Nucleophilic Substitution and Elimination.

### CHEM 322 Organic Chemistry II - Professor Kathleen V. Kilway. CHAPTER 14 Substitution Reactions of Aromatic Compounds

CHEM 322 Organic Chemistry II - Professor Kathleen V. Kilway "Organic Chemistry" by Maitland Jones, 4 th edition Chapter 14 Homework: 1, 2, 5, 7, 13, 19, 20, 23, 26, 27, 28, 30, 31, 34, 35, 36, 41, 46,

### 1. What is the hybridization of the indicated atom in the following molecule?

Practice Final Exam, Chemistry 2210, rganic Chem I 1. What is the hybridization of the indicated atom in the following molecule? A. sp 3 B. sp 2 C. sp D. not hybridized 2. Name the functional groups in

### 11.4 NUCLEOPHILIC SUBSTITUTION REACTIONS OF EPOXIDES

.4 NUEPII SUBSTITUTIN REATINS F EPXIDES 495 (d When tert-butyl methyl ether is heated with sulfuric acid, methanol and -methylpropene distill from the solution. (e Tert-butyl methyl ether cleaves much

### 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

### 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

### 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

### Chapter 6 An Overview of Organic Reactions

John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 6 An Overview of Organic Reactions Why this chapter? To understand organic and/or biochemistry, it is necessary to know: -What occurs -Why and

### 1 General introduction

General introduction Peptides and peptidomimetics _ 1 1 General introduction 1.1 Peptides and peptidomimetics umerous small and large peptides, which are sequence and length-specific polymers composed

### Acids and Bases: Molecular Structure and Acidity

Acids and Bases: Molecular Structure and Acidity Review the Acids and Bases Vocabulary List as needed. Tutorial Contents A. Introduction B. Resonance C. Atomic Radius D. Electronegativity E. Inductive

### 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

### 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

### 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

### Nucleophilic Substitution

8 CAPTER UTLINE 8.1 Functional Group Transformation by Nucleophilic Substitution 307 8.2 Relative Reactivity of alide Leaving Groups 309 8.3 The S N 2 Mechanism of Nucleophilic Substitution 310 8.4 Steric

### 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