| abstract |
The glycinamide of the formulais reacted with the dioxolane of the formulawherein L is a leaving group such as iodo, bromo, alkylsulfonyloxy, or arylsulfonyloxy to give the dioxolane of the formulaTreating the dioxolane of formula III under aqueous refluxing conditions followed by exchanging the dioxolane acetal with a dimethoxy acetal and introduction of the methyl ester gives (S)-2-amino-6,6-dimethoxyhexanoic acid, methyl ester which is an intermediate in the preparation of the dual inhibitor [4S-[4alpha(R*),7alpha,10abeta]]-octahydro-4-[(2-mercapto-1-oxo-3-phenylpropyl)-amino]-5-oxo-7H-pyrido[2,1-b][1,3]thiazepine-7-carboxylic acid. Also disclosed are storage stable salts of (S)-2-amino-6, 6-dimethoxyhexanoic acid, methyl ester. |