An efficient synthesis of enantiomerically pure 2-[(2 R)-arylmorpholin-2-yl]ethanols, key intermediates of tachykinin receptor antagonist

Abstract

We report herein an efficient and practical synthetic method for the preparation of enantiomerically pure 2-[(2 R)-arylmorpholin-2-yl]ethanols 1a– d, key intermediates of tachykinin receptor antagonist. Sharpless catalytic asymmetric dihydroxylation of 4a– d was employed to introduce the required absolute stereochemistry, and cyclization of 7a– d was accomplished by the Mitsunobu reaction.