Kita Y, Futamura J, Ohba Y, Sawama Y, Ganesh JK, Fujioka H. 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.
J Org Chem 2003;
68:5917-24. [PMID:
12868926 DOI:
10.1021/jo034573g]
[Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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.
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