Synthetic applications of chiral 1,3-dioxolan-4-ones and 3-acyloxazolidin-5-ones

Abstract

Chiral dioxolanones derived from α-hydroxy acids can act as chiral acyl anion equivalents for addition to ethyl crotonate, nitroalkenes and butenolide. Subsequent flash vacuum pyrolysis results in loss of CO and Bu tCHO to give products. The related N-acyl and N-thioacyl-1,3- oxazolidin-5-ones formed from α-amino acids behave in a quite different way with loss of CO2 upon pyrolysis leading via N-(thio) acylaziridines to oxazolines and thiazolines. The stereochemistry of these transformations, both relative and absolute, is discussed and a mechanism involving an azomethine carboxylate intermediate is proposed. ©ARKAT.