Electrophilic addition to 4-thio furanoid glycal: a highly stereoselective entry to 2′-deoxy-4′-thio pyrimidine nucleosides
摘要:
4-Thio furanoid glycals with different types of O-silyl protection have been prepared from benzyl 3,5-di-O-benzyl-2-deoxy-1,4-dithio-D-erythro-pentofuranoside. Face-selectivity for PhSeCl- or N-iodosuccimide-initiated addition of a pyrimidine base to the thioglycal was found to be controlled by O-silyl protecting groups. Using the thioglycal protected with a 3,5-O-di-t-butylsilyl group, a highly stereoselective synthesis of beta-2'-deoxy-4'-thio pyrimidine nucleosides has been accomplished. (C) 1998 Elsevier Science Ltd. All rights reserved.