ISSN:
0947-6539
Keywords:
aryl sulfones
;
glycosides
;
radical reactions
;
samarium
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The samarium diiodide reduction of glycosyl pyridyl sulfones bearing a silicon-tethered unsaturated group at the C2-OH position leads to the stereo-specific synthesis of 1,2-cis-C-glycosides in good yield after desilylation. These reactions proceed via an anomeric radical with subsequent 5-exo cyclization. Unlike the corresponding glycosyl phenyl sulfones, the pyridyl derivatives react instantaneously with samarium diiodide and do not require a cosolvent such as hexamethylphosphoramide (HMPA). Under these reaction conditions radical cyclization precedes the second reduction step. Examples of 5-exo-trig and -dig ring closures are given. The synthetic utility of this method was demonstrated by a short synthesis of methyl C-isomaltoside.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.19970030822
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