The Drocedure of Huang and Hui (Nucleosides & Nucleotides 1993, 12, 139–147) was found to give benzyl 3,5-di-O-benzyl-2-deoxy-l,4-dithio-a-L-tfrreo-pentofuranoside (6) rather than the claimed D-erythro isomer. This sugar was converted to an anomeric mixture of the thymine nucleosides. The mixture was separated and the a-anomer (α-10) was found to be cytotoxic, whereas the β-anomer (β-10) was inactive. © 1993, Taylor & Francis Group, LLC. All rights reserved.