[EN] PROCESS FOR PREPARATION OF OPTICALLY ACTIVE 1-ERYTHRO-2-AMINO-1-PHENYL-1-PROPANOL<br/>[FR] PROCEDE POUR PREPARER DU 1-ERYTHRO-2-AMINO-1-PHENYL-1-PROPANOL ACTIF DE MANIERE OPTIQUE
申请人:EMMELLEN BIOTECH PHARMACEUTICA
公开号:WO2005100299A1
公开(公告)日:2005-10-27
An efficient cost-effective process for preparation of l-erythro-2-amino-1-phenyl-1-propanol from l-1-phenyl-1-hydroxy-2-propanone, which comprises converting l-1-phenyl-1-hydroxy-2-propanone to l-1-phenyl-1-hydroxy-2-propanone oxime and reducing the oxime with a catalyst consisting of finely divided nickel and aluminium metals giving good diastereomeric purity and yield.
(2S,4R 5R)-2-Methoxy-4-methyl-3-(4-methylbenzenesulfonyl)-5-phenyl-1,3-oxazolidine (2c) adds trimethylsilyl 1-cycloalkenyl ethers under Lewis acid catalysis with complete induced and high simple diastereoselectivity to yield homochiral oxazolidine-masked 2-formylalkanones.
Stereoselective Alkylations of Chiral Nitro Imine and Nitro Hydrazone Dianions. Synthesis of Enantiomerically Enriched 3-Substituted 1-Nitrocyclohexenes
作者:Scott E. Denmark*、Jeffrey J. Ares
DOI:10.1021/jo801790r
日期:2008.12.19
Dianions of chiral nitro imines (generated by a combination of LDA and s-BuLi) underwent diastereoselective alkylation with methyl, butyl, isopropyl, allyl, and methallyl iodides. In contrast to the behavior of simple metalloenamines, the most selective auxiliary contained no coordinating groups but did possess a large steric difference between the two substituents. The yield and selectivity of the
Asymmetric synthesis of butenolide and butyrolactone derivatives
作者:Andrew Pelter、Robert S. Ward、Abdulkadir Sirit
DOI:10.1016/0957-4166(94)80085-5
日期:1994.9
presence of Lewis acids to afford homochiral 2(5H)-furanone derivatives. The structures of these products have been determined using nmr spectroscopy and, where possible, by X-ray analysis. Preliminary experiments have been carried out involving conjugate addition to these unsaturated lactones, demonstrating their potential as substrates for natural product synthesis.
Stereoselective Reactions. 25. Enantioselective Deprotonation of Prochiral 4-Substituted Cyclohexanones by Chiral Chelated Lithium Amides
作者:Ryuichi Shirai、Daisaku Sato、Kazumasa Aoki、Masahide Tanaka、Hisashi Kawasaki、Kenji Koga
DOI:10.1016/s0040-4020(97)00288-3
日期:1997.4
4-substituted cyclohexanones (4a∼d) by chiral chelated lithium amides (8a≈k) in the presence of excess trimethylsilyl chloride was realized to give the corresponding chiral silyl enol ethers (6a∼d) in up to 89% ee. It is shown that enantioselectivity of the reaction is dependent on the solvent used, but becomes almost independent on the solvent in the presence of HMPA. The sense of asymmetric induction