Stereoselective allylation reactions of acyclic and chiral α-amino-β-hydroxy aldehydes
摘要:
Stereoselective allylation reactions of acyclic and chiral alpha-amino-beta-hydroxy aldehydes affording chiral beta-amino-alpha,gamma-diols are described. Several Lewis acids (BF3-OEt2, SnCl4, TiCl4, ZnCl2, and MgBr2-OEt2) were employed to mediate the allylation reactions. The reactions of anti-oc-NHCbz-B-OTBS substrates mediated by SnCl4 afforded syn-selective products. The same reaction conditions also gave satisfactory results for the reactions of syn-alpha-NHCbz-beta-OTBS substrates. The mechanism involves alpha-chelation between the amido group and aldehyde oxygen. (C) 2017 Elsevier Ltd. All rights reserved.
Biomimetic Total Synthesis and Antimicrobial Evaluation of Anachelin H
作者:Karl Gademann、Yann Bethuel、Hans H. Locher、Christian Hubschwerlen
DOI:10.1021/jo701402b
日期:2007.10.1
biomimetic totalsynthesis of the iron chelator anachelin H isolated from the cyanobacterium Anabaena cylindrica is reported. A first generation approach delivered one enantiomeric series of the polyketide fragment. Comparison of the 1H NMR data suggested the relative configuration of this anachelin fragment. The relative and absolute configuration of anachelin H was then established by totalsynthesis. A