Asymmetric synthesis of tetrahydrolipstatin and valilactone
摘要:
The highly diastereoselective aldol reaction between acyl complexes of the iron chiral auxiliary [(eta(5)-C5H5)Fe(CO)(PPh3)] and beta-hydroxy aldehydes (obtained via a Noyori asymmetric hydrogenation), followed by a tandem oxidative decomplexation-cyclisation process gives access to beta-substituted and alpha,beta-disubstituted beta-lactones in high ee. This methodology has been employed in the asymmetric syntheses of tetra hydrolipstatin and valilactone. (C) 2008 Elsevier Ltd. All rights reserved.
A new catalytic asymmetric approach to polyfunctional aldol products mediated by zinc organometallics
摘要:
The catalytic asymmetric addition of functionalized dialkylzincs to beta-alkoxyaldehydes provides after a short sequence of functional group interconversions aldol products in 40-99% ee. Their stereoselective transformation to either syn- or anti-1,3-diols has been performed.
Novel analogs of prostaglandins with 4-oxo-thiazolidinyl nucleus and
申请人:Merck & Co., Inc.
公开号:US04022794A1
公开(公告)日:1977-05-10
This invention relates to novel 9-thia-, 9-oxothia-, and 9-dioxothia-11-oxo-12-azaprostanoic acid compounds, salts, and derivatives thereof and also to processes for the preparation of such compounds. These compounds have prostaglandin-like biological activity and are particularly useful as renal vasodilators, as platelet aggregation inhibitors, and for the treatment of certain autoimmune diseases.