The first asymmetric synthesis of (+)- and (−)-Dihydrokawain, an α-dihydropyrone isolated from the roots of Piper mythisticum, is reported. (+)-Dihydrokawain is the natural product and is of S-configuration.
Asymmetric Palladium‐Catalyzed Oxycarbonylation of Terminal Alkenes: Efficient Access to β‐Hydroxy Alkylcarboxylic Acids
作者:Bing Tian、Xiang Li、Pinhong Chen、Guosheng Liu
DOI:10.1002/anie.202104252
日期:2021.6.25
leading to high reactivity and excellent enantioselective control. Compared to the conventional methods, the reaction itself features alkenes as easily prepared starting materials, mild and operationally simple reaction conditions, and insensitivities to air and water. Moreover, this method allows for broad alkene substrate scope, excellent regio- and enantioselectivities, scalabilities and a wide array
New chiral acetate imide enolate for stereoselective aldol reactions
作者:Claudio Palomo、Mikel Oiarbide、Alberto González、Jesús M. García、Fabienne Berrée、Anthony Linden
DOI:10.1016/0040-4039(96)01520-1
日期:1996.9
The chiral imide acetate 4 reacts upon lithium and titanium enolate formation conditions with aldehydes in a stereoselective manner. Remarkably, aldols obtained from aromatic and α,β-unsaturated aldehydes exhibited opposite stereochemistry than those obtained from aliphatic aldehydes.
Enantioseparation of 3-hydroxycarboxylic acids viadiastereomericsaltformation was demonstrated using 2-amino-1,2-diphenylethanol (ADPE) and cinchonidine as the resolving agents. Racemic 3-hydroxy-4-phenylbutanoic acid (rac-1), 3-hydroxy-4-(4-chlorophenyl)butanoic acid (rac-2), and 3-hydroxy-5-phenylpentanoic acid (rac-3) were efficiently resolved using these resolving agents. Moreover, the successive
[EN] STEREOSPECIFIC BIOCONVERSION OF BENZYL ACETOACETATE TO BENZYL-(S)-(+)-3-HYDROXYBUTYRATE<br/>[FR] BIOCONVERSION STEREOSPECIFIQUE DU BENZYLACETOACETATE EN BENZYL-(S)-(+)-3-HYDROXYBUTYRATE
申请人:MERCK & CO., INC.
公开号:WO1997032031A1
公开(公告)日:1997-09-04
(EN) A bioconversion process where benzyl acetoacetate is converted to benzyl-(S)-(+)-3-hydroxybutyrate.(FR) L'invention porte sur un procédé de bioconversion du benzylacétoacétate en benzyl-(S)-(+)-3-hydroxybutyrate.