ASYMMETRIC MICHAEL ADDITION OF A GLYCINE SYNTHON TO METHYL-METHACRYLATE, MEDIATED BY DISODIUM TADDOLATE

The disodium salt of (4R,SR)-(TADDOL), 3, can be used as a mediator in the asymmetric Michael reaction, e.g. 1,4-addition of a glycine synth on 1 to methyl methacrylate 2, mediated by 3 (10-100 mol%), gives a di astereoisomeric excess of the corresponding product 4 up to 65% and an enantiomeric purity ca. 28%; (2S,4R)-4-methylglutamic acid (ee greate r than or equal to 85%), 6, was obtained starting from (2S,4R)-4 (ee 2 8%) through the recrystallization and decomposition of the latter.