Synthesis of intermediates in the formation of hydroxy piperidines and 2-azido lactones from D-erythrose

A new stereodivergent synthesis towards piperidine iminosugar and azido lactones is described. The reaction of ethylidene-D-erythrose with amide sulfur ylides gave two isomeric trans-epoxyamides which were converted to 2-azido derivatives. Hydrolysis of the allo isomer gave 2-azido-1,4-lactone while the manno isomer gave the open chain epoxyamide. The latter gave a DMJ derivative in two steps. Direct hydrolysis of ethylidene epoxyamides gave the 3,6-anhydro glyconamides. (c) 2008 Elsevier Ltd. All rights reserved.