SYNTHESE DE NUCLEOSIDES PYRIMIDIQUES NON PROTEGES EN O-2'A PARTIR DE SULFITES CYCLIQUES EN C-1-C-2

Article abstract of DOI:10.1016/0008-6215(88)80080-6

Treatment of 3,5,6-tri-O-benzoyl-α-D-glucofuranose 1,2-sulfite with an excess of bis(trimethylsilyl) uracil, in fusion processes without any catalyst, afforded an excellent yield of 1-(3,5,6-tri-O-benzoyl-2-O-trimethylsilyl-β-D-glucopyranosyl)uracil, which was readily hydrolyzed in slightly acid conditions to give in almost quantitative yield 1-(3,5,6-tri-O-benzoyl-β-D-glucofuranosyl)uracil.This new synthetic method for nucleosides unprotected at O-2' was also tested in other sugar series.In some cases, only the 1',2'-trans-nucleosides were obtained, but in others, small yields (3-10percent) of 1',2'-cis-nucleosides were detected.The α-to-β ratio seems to be dependent on the reaction temperature. 2,4-Dimethoxypyrimidine also reacted with sugar 1,2-sulfites and 4-O-methyl-1-(3,5,6-tri-O-benzyl-β-D-glucopyranosyl)-2-pyrimidinone was prepared in 85percent yield from 3,5,6-tri-O-benzyl-α-D-glucopyranose 1,2-sulfite.