Asymmetric Synthesis of 3′-Carbomethoxymethyl-3′-deoxythymidine via Radical Cyclization.

Abstract An efficient asymmetric synthesis of 3′-C-carbomethoxymethyl- 3′-deoxythymidine 2, using a highly stereocontrolled radical cyclization from bromoacetai 7 to furanose 8, followed by a dimethylboron bromide mediated nucleoside formation, is described. A 96:4 β-selectivity was observed for thionoeste-controlled base attachment.