The first enantioselective total synthesis of (+)-preussin B and an improved synthesis of (+)-preussin by step-economical methods

Abstract

The first enantioselective total synthesis of (+)-preussin B and an improved synthesis of the antifungal alkaloid (+)-preussin are described. Our approach relied on the four step-economical synthetic methods developed in our laboratory: (1) the cis-diastereoselective reductive dehydroxylation of hemiaminals; (2) the direct amide/lactam reductive alkylation; (3) the one-pot N,O-bisdebenzylation-N-methylation; and (4) the one-step synthesis of malimide from malic acid. Both total syntheses are quite concise, which have been achieved in six steps, and gave overall yields of 25.7% and 27.6%, respectively.