An attempt on the synthesis of the clavam skeleton from glycals and isocyanates

Abstract

N-Protected 2-C:1- N-carbonyl-2-deoxy-glycopyranosylamines 12, 13, and 16 were subjected to the two-step oxidation to afford dicarboxylic acids 20, 21, and 30. Decarboxylation of the group located in a malonyl system with the β-lactam carbonyl group failed to give 1,4-disubstituted azetidinones. Bromides 45, 46, obtained from 30 by standard transformations, subjected to fluoride-anion-induced cyclization, failed to form clavam 53.