Efficient Preparation of a Key Intermediate in the Synthesis of Roxifiban by Enzymatic Dynamic Kinetic Resolution on Large Scale

Abstract

Additional information is presented for the transformation of a kinetic resolution into a dynamic kinetic resolution of the isobutyl ester 5b to form the acid 2 in high yield and ee via the intermediacy of a thioester 6c, (Pesti, J. A.; Yin, J.; Zhang, L.-H; Anzalone, L. J. Am. Chem. Soc. 2001, 123, 11075−11076.). The development of optimized reaction conditions for the preparation of 6c, its dynamic kinetic resolution to 2, and the scale-up of both reactions into a pilot plant are described.