Selective Wittig olefination in aqueous media for the rapid preparation of unsaturated 7,3-lactone-α-d-xylofuranose derivatives

Abstract A highly efficient and rapid protocol for the preparation of the title compounds 1a and 1b from d -glucose derivatives 2a and 2b , respectively, is reported. To this end, highly selective Wittig olefination in aqueous media was developed for the elaboration of α,β-unsaturated acids 5a and 5b , which when treated with DCC, lactonization was accomplished and the title compounds 1a and 1b were obtained in only three sequential steps with overall yields of 85% and 88%, respectively. Additionally, the Z-selectivity was studied by analyzing conformational models of its corresponding oxophosphorinane intermediaries.