SYNTHESES, STRUCTURE ET REACTIVITE VIS-A-VIS DE NUCLEOPHILES DU 1,2:3,4-DISULFITE DE β-L-ARABINOPYRANOSE

Article abstract of DOI:10.1016/0008-6215(88)80079-X

Treatment of L-arabinose, at low temperature, with thionyl chloride in the presence of pyridine afforded, in 93percent yield, a mixture of the four diastereoisomeric β-L-arabinopyranose 1,2:3,4-disulfites.Configurations at the sulfur atoms were determined for each isomer by high resolution 1H-n.m.r. spectroscopy.Reaction of these compounds with various nucleophiles, including bis(trimethylsilyluracil), led in high yields to 1,2-trans-glycosides, unprotected at O-2 and having a cyclic 3,4-sulfite group.The latter compound was substituted by azide ion to give, after benzoylation, 1-(3-azido-2,4-di-O-benzoyl-3-deoxy-α-L-lyxopyranosyl)uracil from 1-(O-trimethylsilyl-α-L-arabinopyranosyl 3,4-sulfite)uracil.Hydrolysis of the cyclic sulfite group of 1-(α-L-arabinopyranosyl 3,4-sulfite)uracil afforded 1-(α-L-arabinopyranosyl)uracil in almost quantitative yield.Thus, this nucleoside was synthesized in 77percent overall yield from L-arabinose via β-L-arabinopyranose 1,2:3,4-disulfite.