uridine (11) with dimethyldioxirane proceeded from the α-face to give the 1‘,2‘-α-epoxide 12. Upon reacting with organoaluminum reagents, the 1‘,2‘-α-epoxide 12 underwent preferential syn-opening of the epoxide ring to yield the β-anomers of 1‘-methyl- (13β), 1‘-ethyl- (14β), 1‘-isobutyl- (15β), 1‘-ethynyl- (16β), 1‘-vinyl- (17β), and 1‘-phenyl- (18β) uridine derivatives, although the corresponding α-anomers
Stereoselective Synthesis of 1‘-<i>C</i>-Branched Arabinofuranosyl Nucleosides via Anomeric Radicals Generated by 1,2-Acyloxy Migration
作者:Kazuhiro Haraguchi、Yoshiharu Itoh、Kouichiro Matsumoto、Kyoko Hashimoto、Kazuo T. Nakamura、Hiromichi Tanaka
DOI:10.1021/jo020620d
日期:2003.3.1
formation at the anomeric position of uracil and adenine nucleoside has been accomplished through reaction of the anomericradical, generated by 1,2-acyloxy migration, with a radical acceptor. The present method consists of the following steps: (1) electrophilic addition (bromo-pivaloyloxylation) to 3',5'-O-(1,1,3,3-tetraisopropyldisiloxane-1,3-diyl)-protected 1',2'-unsaturated nucleoside, (2) tin radical-mediated