N1–C4 β-Lactam Bond Cleavage in the 2-(Trimethylsilyl)thiazole Addition to β-Lactam Aldehydes: Asymmetric Synthesis of Spiranic and Tertiary α-Alkoxy-γ-keto Acid Derivatives
作者:Benito Alcaide、Pedro Almendros、María C. Redondo
DOI:10.1002/ejoc.200700231
日期:2007.8
Starting substrates, enantiopure spiranic or 3-substituted 3-alkoxy-4-oxoazetidine-2-carbaldehydes, were prepared from (R)-2,3-O-isopropylideneglyceraldehyde derived azetidine-2,3-diones by sequential Barbier-type addition reactions followed by hydroxy functionalization and aldehyde unmasking. The reaction between the above β-lactamaldehydes and 2-(trimethylsilyl)thiazole (TMST) gave as major products