Synthesis of sulfur-containing analogues of #alpha#GalNAc(tn-antigen) and #beta#Gal1,3-#alpha#GalNAc(t-antigen)

摘要

A method for the preparation of thio-analogues of the T- and Tn-antigen was developed.Thus,starting from a known N-acetamido-glucoside derivative,the epidithio analogue of the Tn-antigen was accessible in four-step reaction sequence.The corresponding epidithio analogue and the thioanhydro derivative of the T-antigen were synthesized starting from a disaccharide derivative.For the preparation of the epidithio analogue the sulfur atoms were introduced via thiocyanates in a stepwise fashion,using meaylate as the leaving group at C-6 and triflate as the leaving group at C-4 inthe reducing carbohydrate moiegy.The synthesis of the thioanhydro analogue was achieved by introducing a thiocyanate group at C-6 into the glucose moiety,followed by subsequent displacement of a mesylate group at C-4 under iversion of configuration utilizing sodium methoxide.