Asymmetric and diastereodivergent approach to key intermediates for the synthesis of homopumiliotoxin 223G and epiquinamide isomer
作者:Le Anh Tuan、Hyeyoung Pyeon、Guncheol Kim
DOI:10.1016/j.tetlet.2009.10.098
日期:2010.1
A stereoselective reaction followed by a sequential cyclization route has been used in the divergent synthesis of 1-hydroxyquinolizidione isomers. Sharpless asymmetric dihydroxylation afforded hydroxyl lactone and the following mesylation provided the required precursor for cyclization. (C) 2009 Elsevier Ltd. All rights reserved.
<i>N</i>,<i>N</i>-Acetals as <i>N</i>-Acyliminium Ion Precursors: Synthesis and Absolute Stereochemistry of Epiquinamide
作者:Marloes A. Wijdeven、Roel Wijtmans、Rutger J. F. van den Berg、Wim Noorduin、Hans E. Schoemaker、Theo Sonke、Floris L. van Delft、Richard H. Blaauw、Richard W. Fitch、Thomas F. Spande、John W. Daly、Floris P. J. T. Rutjes
DOI:10.1021/ol801490m
日期:2008.9.18
A stereoselectivesynthesis of (+)-epiquinamide is presented in combination with determination of the absolute configuration of the natural product. Key steps in the sequence involved chemoenzymatic formation of an enantiomerically pure cyanohydrin, reductive cyclization to the corresponding cyclic N,N-acetal, and subsequent conversion into a suitable N-acyliminium ion precursor to enable construction