Me Me Me Indroduction: Steganone -Isolation from Steganotaenia araliacea in 1972 from Kupchan -Belong to the category of lignans Biological Properties: -Significant activity in vivo against P-388 leukemia in mice and in vitro against cells derived from human carcinoma of the nasopharynx Synthesis of : -First synthesis in 1976 by Kende -ine total synthesis of racemic stegane natural products. -Five total synthesis of asymmetric stegane natural products Me Me Me R R: Ac Steganacin R: Steganol R: C steganangin Total synthesis of Steganacin (Kende et al. JACS, 1976, 98, 267) on enolic oxidation methodology VF3 45% Me Me C 2 Et Me Me MsCl, Et3 C 2 Et Me C 2 Et C 2 Et Me Me Me Me C 2 Et C 2 Et C 2 a, DMF 0 0 C 52% Cr 3 -pyridine 60% Ms Et 2 C Me C 2Et Me 1.BS-CCl 4, benzoyl peroxide 2.AgCCF 4 3.aq Et 3 Me ac(c2et)2, Ar reflux Me Me C 2 Et C 2 Et Me
Total synthesis of Steganacin Kende et al.(continue) on enolic oxidation methodology C 2 Et 1.K- 2 C 2 Et 2.200 0 C Me 95% Me Me - -C 2 ab4 C Me Me Me Me 77% Me Me Me Me Me epi-steganole Ac Ac 2 -pyridine Me Me Me Me Me Me Steganacin steganole ratio 55:45 Total synthesis of Steganacin (Ziegler et al. JACS, 1980, 102, 790) Application of Ullmann Reaction MeI, 2 acetone t-buk, t-bu 73% S Me Me 1.n-BuLi, TF 2.CuI. (Et) 3 P Me Me M C 2 Me C 2 Me Me 1. S M=Li M=CuP(Et) 3 Me Me 1.Raney i, 2 1atm 2.C 6 5 3, DCM C 2 Me Me Me C 2 Me I -78 0 C 2.20%Ac 3.malonate,reflux 82% Me Me Me Y Y=SC 2 C 2, Z=C 6 11 Y=SC 2 C 2, Z= Y=SC 2 C 2, Z=C(C 2 Me) 2 Me Me Me Steganacin Z C 2 Me C 2 Me
Total synthesis of Steganacin Ziegler et al.(continue) Application of Ullmann Reaction Me Me Me C 2 Me C 2 Me K, 2 xylenes reflux Me Me Me C ratio 1:1 C Total synthesis of Steganacin (by Raphael. J. Chem Soc Perkin Trans 1, 1977, 1674) Use of phenanthrene derivatives aq. DMS 74% CCl Me Me Me Me C 2 Bu t Pyrrolidine 88% LDA, TF Me Me Me Me R 2 C 2 Bu t Me Me Me Me Me Me Me isosteganone hv liq. 3 t-buk R 2 C 2 Me C 2 Me R 2 C 2 Me 65% Me 91% Me C 2 Me Me Me Me Me
Total synthesis of Steganacin by Raphael (continue) Use of phenanthrene derivatives Me Me Me 1.Raney i 2 2. Jones oxidation 3.Base 95% R 2 Me Me C 2 Me C 2 Me Me Cl Me 90% Me Me 1.K, C 2.Jones oxidation C 75% Me Me Me C 2 Me Steganacin Me 23% overall yield Me Me Total synthesis of Steganone Magnus et al. (J. Am. Chem. Soc. 1985, 4984) A [7,3] ring expansion Me Me Me Me Tl(CCF 3 ) 3 TFA, 0 0 C 43% Me 2 CC 2 P()(Et) 2 a C 2 Me Me Me Me Me 2 S ()C 3 I - a 82% C 2 Me Me Me Et Et DIBAL P Me Me Me C 2 Me Me Me Me Me piperonal a 38% 2:1 C 2 Me C 2
Total synthesis of Steganone Magnus et al. (continue) A [7,3] ring expansion Me Me Me Jones oxidation Me Me C 2 Me 1.Ac, Aca, Cl 4, 45 0 C Me 2.B 3, TF 3. 2 2, a 4. K 2 C 3, 2 Me C Me Steganone Asymmetric Total synthesis of (-)Steganone Robin et al. (Tetrahedron Lett., 1980, 21, 2709) ai 4 t Bu Me Tr Ar 2 C LDA, ArC 2 TF C Ar 2 C I 2, CF 3 C 2 Ag Me Me LDS, Ar 10 0 C Tr 1.LA, TF 2. 2, Pd/C I Me Ar 2 C Me C 2 C 2 C Cu, 230 0 C C 2 Me Me Me Me 1.Cr 3, acetone 2.C, K 3.Cr 3, acetone xylenes reflux Me Me Me Me Me Me (-)Steganone
Asymmetric Total synthesis of (-)Steganone Meyers et al. (JACS., 1987, 109, 5447) Me Me Me 1.C 2 2 Cl 2, 3 2.Et 3 BF 4 Mg 1. 2.MeMg C 2 Me Me Me Me Me Me Me Me Me Me Me 2 Me 85% Et Me Me Me C 2 a Me Me Me I Mea Cu Me Me Me Me Me Me Me 9% Me Me Me C Me Me Me Me 1.BS 2. - C(C 2 Me) 2 t-buk Me Me Me Me Me Me Me C 2 Me C 2 Me 1. 2 S 4 2.LA C 2 Me C 2 Me Me Me 1.( 2 P) 3 RhCl 2.gCl 2 -g 3.C 5 5 3 1. - 2.C 2 2 3.C 4.Jones ox Me Me Me (-)Steganone Me C 2 Me C 2 Me