OUVERTURE REGIOSPECIFIQUE D'UN OXIRANE PREPARE A PARTIR DU D-XYLOSE PAR DES CARBANIONS SOUFRES; SYNTHESE DE C-NUCLEOSIDES BRANCHES

Article abstract of DOI:10.1016/S0040-4020(01)98931-8

Two methods using the readily accessible D-xylose have been developed for the synthesis of epoxides 4 and 5.The oxirane 5 was considered as a good intermediate for the preparation of 3'-C-substituted nucleosides.The crucial step for the synthesis of 32 is the regiospecific opening of the epoxide 5 using two carbanions, derived from either dithiane or bis(phenylthio)methane, followed by desulphurisation leading to 17.The exclusive opening of the epoxide in 5 was unequivocally established by (13)C NMR spectroscopy.