Stereoselective alkylation of chiral pyrrolidin-2-ones leading to novel conformationally restricted analogues of 3-methylaspartic acid: a computational investigation

摘要

The stereoselectivity of the alkylation of chiral pyrrolidin-2-ones leading to conformationally restricted analogues of 3-methylaspartic acid was investigated using density functional theory calculations: The overall stereo-control is regulated by the relative stability of the lithium enolate intermediates which are also involved in the rate-determining step leading to the methylaspartic acid derivative. The computed results explain the observed data and the different diastereoselectivity can be ascribed to the nature of the alkylating group.