Synthesis of (3R,4S,5S,9S)-3,5,9-trihydroxy-4-methylundecanoic acid δ-lactone
摘要:
Radical-mediated opening of a chiral trisubstituted epoxy alcohol using cp(2)TiCl furnished the '2-methyl-1,3-diol' moiety with the desired stereochemistry, which led to a total synthesis of (3R,4S,5S,9S)-3,5,9-trihydroxy-4-methylundecanoic acid delta-lactone 1. (C) 2004 Elsevier Ltd. All rights reserved.
Synthesis and evaluation of a broad range of new chiral phosphine–carbene ligands for asymmetric hydrogenation
摘要:
A straightforward and gram scale synthesis (six-step synthesis from enantioenriched beta-hydroxy esters) of new structurally simple phosphine-carbene ligands bearing a single stereogenic centre has been achieved. Enantioselectivities of up to 60-63% could be achieved in the hydrogenation of methylstilbene and dehydroaminoacids when the reactions were performed under 20-50 bar hydrogen pressure. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of Chiral β<sup>3</sup>-Aminoxy Peptides
作者:Dan Yang、Yu-Hui Zhang、Bing Li、Dan-Wei Zhang
DOI:10.1021/jo049174f
日期:2004.10.1
A series of chiral beta(3)-aminoxy acids or amides with various side chains have been synthesized via two different approaches. One is the Arndt-Eistert homologation approach, using chiral alpha-aminoxy acids as starting materials. The other approach, utilizing the enantioselective reduction of beta-keto esters catalyzed by baker's yeast or chiral Ru(II) complexes, produces chiral beta(3)-aminoxy acids with nonproteinaceous side chains. The oligomers of beta(3)-aminoxy acids can be readily prepared using EDCI/HOAt as the coupling reagent.