De novo asymmetric syntheses of C-4-substituted sugars via an iterative dihydroxylation strategy
作者:Md. Moinuddin Ahmed、George A. O’Doherty
DOI:10.1016/j.carres.2006.03.024
日期:2006.7
highly efficient route to various C-4 substitutedsugar lactones has been developed. The key to the overall transformation is the sequential osmium-catalyzed dihydroxylation reaction of substituted 2,4-dienoates and an allylic substitution at the C-4 position. When the Sharpless AD-mix procedure is used in a matched sense for the second dihydroxylation reaction, it results in an exceedingly diastereo-
Expeditious and stereoselective synthesis of chiral trans-β-hydroxy-δ-lactone systems starting from γ,δ-epoxy acrylates is described which involves the regioselective ring opening of an epoxide and the intramolecularconjugateaddition of a hemiacetalalkoxide anion of δ-hydroxy-α,β-unsaturated esters as key steps.