Enantio- and diastereoselective transformations of cycloheptatriene to sugars and related products
摘要:
Both meso diastereomers of 6-[(tert-butyldimethylsilyl)oxy]-2-cycloheptene-1,4-diol, prepared from cycloheptatriene, have been enzymatically asymmetrized by conversion to monoacetates using Pseudomonas cepacia lipase in isopropenyl acetate. A study of protecting group manipulations, diastereoselective oxidations, and regioselective ring openings utilizing these enantiopure monacetates which results in the synthesis of all possible methyl 2,4-dideoxyhexopyranosides is described.
Enantio- and diastereoselective transformations of cycloheptatriene to sugars and related products
摘要:
Both meso diastereomers of 6-[(tert-butyldimethylsilyl)oxy]-2-cycloheptene-1,4-diol, prepared from cycloheptatriene, have been enzymatically asymmetrized by conversion to monoacetates using Pseudomonas cepacia lipase in isopropenyl acetate. A study of protecting group manipulations, diastereoselective oxidations, and regioselective ring openings utilizing these enantiopure monacetates which results in the synthesis of all possible methyl 2,4-dideoxyhexopyranosides is described.
Enantioselective Synthesis of γ-Hydroxyenones by Chiral Base-Catalyzed Kornblum DeLaMare Rearrangement
作者:Steven T. Staben、Xin Linghu、F. Dean Toste
DOI:10.1021/ja065464x
日期:2006.10.1
A cinchona-alkaloid catalyzed asymmetric Kornblum DeLaMare rearrangement has been developed. Thus, enantioenriched 4-hydroxyenones are prepared from dienes by a two-step sequence involving photochemical dioxygenation and chiral base-catalyzed desymmetrization of the resulting endoperoxides.