Total synthesis and determination of the stereochemistry of 2-amino-3-cyclopropylbutanoic acid, a novel plant growth regulator isolated from the mushroom Amanita castanopsidis Hongo
[EN] BRIDGED TRICYCLIC CARBAMOYLPYRIDONE COMPOUNDS AND THEIR PHARMACEUTICAL USE [FR] COMPOSÉS DE CARBAMOYLPYRIDONE TRICYCLIQUE PONTÉS ET LEUR UTILISATION PHARMACEUTIQUE
The synthesis of various types of optically active α-(allenylsilane-containing)glycines via a chirality-transferring ester-enolate Claisen rearrangement of α-acyloxy-α-alkynylsilanes is described. The conversion of the rearranged products into the optically active silicon-free α-(allenyl)- and α-substituted-α-(allenyl)glycines was achieved by the removal of the Me2PhSi- or TMS group from the allene
Asymmetric synthesis of N,O-diprotected (2S,3S)-N-methyl-δ-hydroxyisoleucine, noncoded amino acid of halipeptin A
作者:Irene Izzo、Elvira Avallone、Luca Della Corte、Nakia Maulucci、Francesco De Riccardis
DOI:10.1016/j.tetasy.2004.02.008
日期:2004.4
The first enantio selective synthesis of N,O-diprotected(2S,3S)-N-methyl-delta-hydroxyisoleucine 4, starting from readily available (tert-butyldimethylsilyl)-2-butyn-1-ol 5, is described. The key steps of this stereochemical flexible synthetic route involve a silyl-assisted [3,3]-sigmatropic rearrangement, for the establishment of the correct stereoisomeric pattern, and a triethylsilane-TFA induced reduction of an oxazolidinone intermediate, to yield the requested N-methylation. (C) 2004 Elsevier Ltd. All rights reserved.