Asymmetric synthesis of β-lactams and n-benzoyl-3-phenylisoserines via the staudinger reaction

Abstract

Reaction of benzaldimine 5 derived from 2,3,4,6-tetra-O-acetyl-β-D-galactoseamine with acid chloride 6 yields cis β-lactam 7 as a single diastereoisomer. Hydrolysis of β-lactam 7 followed by N-benzoylation provides access toward N-benzoyl (2S,3R)-3-phenylisoserine 9. N-Benzoyl-3-phenylisoserines are important building blocks for the semi-synthesis of the anti-cancer agent taxol.