作者:Basil Hartzoulakis、David Gani
DOI:10.1039/p19940002525
日期:——
Arndt-Eistert homologation of suitably-protected (2S,3S)-3-methylaspartic acid occurs with retention of configuration at C-3 to give, ultimately, (2S,3R)-3-methylglutamic acid. (2S,3R)-3- Methylglutamic acid was also prepared in good yield via the conjugate addition of the lithiated anion of the bis-lactim ether. of cyclo-(R-Val-Gly) to methyl (E)-butenoate. The analogous reaction performed using isopentyl (Z)-butenoate ultimately gave (2S,3S)-3-methylglutamic acid. Both conjugate additions occurred with high diastereoselectivity.