Process for synthesis of syn azido epdxide and its use as intermediate for the synthesis of amprenavir and saquinavir

摘要

A novel synthetic route to the syn-azido epoxide of formula 5 includes cobalt-catalyzed hydrolytic kinetic resolution of a racemic mixture of the azido-epoxide. Reaction steps include subjecting an allylic alcohol to epoxidation with mCPBA to obtain a racemic epoxy alcohol; ring opening the epoxy alcohol with azide anion to obtain an anti-azido alcohol, which can then be selectively tosylated at the primary alcohol; treating the tosylate with base to obtain the racemic azido-epoxide; and subjecting the racemic azido-epoxide to cobalt-catalyzed hydrolytic kinetic resolution to obtain the syn-azido epoxide of formula 5. The compound of formula 5 may be used as a common intermediate for the asymmetric synthesis of HIV protease inhibitors, such as Amprenavir, Fosamprenavir, Saquinavir, and formal synthesis of Darunavir and Palinavir.