Asymmetric synthesis of 2,4,5- substituted prolines through 1,3-dipolar addition reaction of N-arylidene menthyl esters of α-aminoacid with methyl acrylate

Abstract

Proline and its derivatives constitute the important organic entities as organocatalyst, ACE inhibitors, bioactive molecules/intermediates to bioactive molecules as well as components of various natural products e.g. Kainic acid, (-)-domoic acid, etc. Due to its wide range of utility extensive studies have been made for the synthesis of 2, 3, 4 or 5 substituted prolines. One pot synthesis of 2,4,5-substituted prolines through 1,3-dipolar addition of various amino acids with homochiral acrylate has also been carried out successfully. Herein we wish to report the 1,3-dipolar addition of Schiff bases, where chiral auxiliary has been introduced in the Schiff bases and 1,3dipolar addition with methyl acrylate leading to the synthesis of 2(S),4(S),5(R)-substituted prolines has been achieved successfully.