Temperature controlled stereoselectivity in the synthesis of 5-halo-2′-deoxyuridine derivatives

Abstract

A series of α- and β-5-halo-2′-deoxyuridine derivatives were prepared with high anomeric selectivity using the conventional silylbase glycosylation method and taking advantage of the 3′-O-(N-acetyl)glycyl protection group and temperature control. Reactions performed at −7°C gave as much as 87% of the β-anomers, while an overnight reaction at 30°C gave up to 95% of the α-anomers.