Concise Enantioselective Synthesis of (+)‐FR66979 and (+)‐FR900482: Dimethyldioxirane‐Mediated Construction of the Hydroxylamine Hemiketal

Abstract

The remarkable one-step deprotection/oxidative cyclization of an eight-membered-ring aminoketone 1 in the presence of dimethyldioxirane gives rise to the unique hydroxylamine hemiketal ring system of FR66979 (2) and FR900482 (3), clinically important antitumor antibiotics. The concise 33-step enantioselective synthesis of 3 is the shortest route reported to date.