ASYMMETRIC-SYNTHESIS OF ALPHA-AMINO PHOSPHONIC-ACIDS BY DIASTEREOSELECTIVE ADDITION OF TRIMETHYL PHOSPHITE ONTO CHIRAL OXAZOLIDINES

A simple and general asymmetric synthesis of alpha-amino phosphonic ac ids is described. The method involves the highly selective addition of trialkyl phosphite onto various chiral oxazolidines. Oxazaphosphorina nes thus obtained with an excellent diastereoselectivity furnish the c orresponding (S)-alpha-substituted amino phosphonic acids in good over all yields and high ee (77-->97%) after simple deprotection.