ChemInform Abstract: An Efficient Synthesis of Enantiomerically Pure 2-[(2R)-Arylmorpholin-2-yl]ethanols, Key Intermediates of Tachykinin Receptor Antagonist.

We report herein an efficient and practical synthetic method for the preparation of enantiomerically pure 2-[(2R)-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.