The rearrangement of 2,3-epoxysulfonates and its application to natural products syntheses: formal synthesis of (-)-aphanorphine and total syntheses of (-)-alpha-herbertenol and (-)-herbertenediol.
The Lewis acid treatment of 2,3-epoxysulfonates with 2,3-dialkyl substituents or 2-alkyl-3-aryl substituents produced the rearrangement products via C3-cleavage of the oxirane ring in high yields. On the other hand, 2-aryl-3-alkyl-2,3-epoxysulfonates produced the products via C2-cleavage of the oxirane ring. The sulfonyloxy groups of the alpha-sulfonyloxy ketones, having a chiral benzylic quaternary carbon center obtained by the rearrangement of 2-alkyl-3-aryl-2,3-epoxysulfonates, were reductively eliminated to give the ketones with a chiral benzylic quaternary carbon center. The method was applied to the formal synthesis of (-)-aphanorphine and total syntheses of (-)-alpha-herbertenol and (-)-herbertenediol.
Kita
Yasuyuki
Y
Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan. kita@phs.osaka-u.ac.jp
Futamura
Junko
J
Ohba
Yusuke
Y
Sawama
Yoshinari
Y
Ganesh
Jnaneshwara K
JK
Fujioka
Hiromichi
H
D000470:Alkaloids / Q000138:chemical synthesis; D001688:Biological Products / Q000138:chemical synthesis*; D001952:Bridged-Ring Compounds / Q000138:chemical synthesis*; D003517:Cyclopentanes / Q000138:chemical synthesis* / Q000737:chemistry; D004852:Epoxy Compounds / Q000737:chemistry*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D010636:Phenols / Q000138:chemical synthesis* / Q000737:chemistry; D011758:Pyrroles / Q000138:chemical synthesis*; D013451:Sulfonic Acids / Q000737:chemistry*
D000470:Alkaloids; D001688:Biological Products; D001952:Bridged-Ring Compounds; D003517:Cyclopentanes; D004852:Epoxy Compounds; D007202:Indicators and Reagents; D010636:Phenols; D011758:Pyrroles; D013451:Sulfonic Acids; C434304:aphanorphine; C482283:herbertenediol; C482284:herbertenol