Diastereoselective synthesis of α-bromo amides leading to diastereomerically enriched α-amino-, α-hydroxy- and α-thiocarboxylic acid derivatives
作者:By Robert S Ward、Andrew Pelter、Dominique Goubet、Martyn C Pritchard
DOI:10.1016/0957-4166(95)00032-k
日期:1995.2
prepared diastereoselectively starting from racemic α-bromo acids, and undergo epimerisation under appropriate conditions leading to an enhanced d.e.. By reacting the individual isomers or the mixture of diastereoisomers with a suitable nucleophile it is possible to obtain α-substituted carboxylic acids, including α-amino- α-hydroxy- and α-thiocarboxylic acid derivatives, in diastereomerically enriched
Diastereoselective addition of allylic reagents to chiral α-ketoimides derived from Oppolzer's sultam
作者:Katarzyna Kiegiel、Janusz Jurczak
DOI:10.1016/s0040-4039(98)02470-8
日期:1999.1
Additions of allylmagnesium chloride and allyl bromide in the presence of zinc dust to N-methyl- and N-phenylglyoxyloyl-(2R)-bornane-10,2-sultam and the Lewis acid-mediated additions of allyltrimethylsilane to these chiral α-ketoimides were studied. High diastereoselection in these reactions was observed, and in the case of the allyltrimethylsilane/TiCl4 additions, a change of direction of asymmetric
Asymmetric reduction of N-methylglyoxyloyl- and N-phenylglyoxyloyl-(2R)-bornane-10,2-sultam
作者:Jarosław Kiegiel、Artur Papis、Janusz Jurczak
DOI:10.1016/s0957-4166(99)00024-5
日期:1999.2
N-Methylglyoxyloyl- (la) and N-phenylglyoxyloyl-(2R)-bornane-10,2-sultam(lb), when reduced under various conditions, afford mixtures of two diastereoisomeric alcohols. In both cases, the reaction conditions lead to excess of both (S) and (R) configuration at the newly created stereogenic center of diastereomeric products have been found. (C) 1999 Elsevier Science Ltd. All rights reserved.
Raszplewicz; Sikorska; Kiegiel, Polish Journal of Chemistry, 2005, vol. 79, # 12, p. 1901 - 1907