Preparation of (4S-(4alpha,7alpha,10Abeta))-4-amino-octahydro-5-oxo-7H- pyrido(2,1-B)(1,3)thiazepine-7-carboxylic acid, methyl ester and salts thereof via novel disulfides

摘要

N-protected-L-homocysteine disulfide of the formula or an activated form thereof is reacted with (S)-2-amino-6,6-dimethoxyhexanoic acid, methyl ester to give the disulfide intermediate of the formula Cleavage of the disulfide bond followed by acid catalyzed cyclization produces the N-protected lactam of formula III which is useful for preparing the pharmaceutically active compound omapatrilat.