Improved stereoselective synthesis of both methyl α- and β-glycosides corresponding to the amino sugar component of the E Ring of calicheamicin γ1(I) and esperamicin A1

Article abstract of DOI:10.1016/S0040-4020(97)00921-6

The monosaccharide component (α and β-anomer) of the E Ring of calicheamicin γ₁(I) and esperamicin A₁ has been synthetized by an efficient and improved stereoselective procedure starting from methyl 2-deoxy-α- and β-D-ribopyranoside. The synthetic procedure makes use, in each case, of a cyclic sulphate and of the regioselective ring opening of an intermediate activated aziridine.