Abstract
Reductive deiodination of 2-deoxy-2-iodo-glycoside is an efficient and practical approach
for the synthesis of 2-deoxyglycosides, which are moieties of bioactive compounds.
However, inseparable diastereoisomers are usually formed in the preparation of 2-deoxy-2-iodo-glycosides
via glycosylation of glycals with alcohols using current methods. To overcome this
problem, a rapid and diastereoselective transformation of glycals and alcohols into
2-deoxy-2-iodo-α-glycosides enabled by I2/PhI(OAc)2 has been developed. 14 glycals, derived from 13 monosaccharides and one disaccharide,
diastereoselectively yielded α-glycosides. Only in two cases the diastereoselectivity
of the glycosylation was poor. The yields of glycosylation range from 73% to 95%,
and the reactions are finished in only five minutes. Investigations for better diastereoselectivity
by comparing I2/Ph(OAc)2- with I2/Cu(OAc)2-mediated glycosylations using UV analysis have been conducted.
Key words
2-deoxy-2-iodo-glycoside - selective glycosylation - glycal - alcohol - iodine - iodobenzene
diacetate