salts induce the kineticresolution of racemic α-substituted unsaturated carboxylicacids through asymmetric protolactonization. Both the lactones and the recovered carboxylicacids are obtained with high enantioselectivities and high S (= kfast/kslow) values. Asymmetric protolactonization also leads to the desymmetrization of achiral carboxylicacids. Notably, chiral phosphonous acid diester not only
手性phospho盐通过不对称的原内酯化诱导外消旋α-取代的不饱和羧酸的动力学拆分。内酯和回收的羧酸均具有高对映选择性和高S(= k fast / k slow)值。不对称的原内酯化也导致非手性羧酸的去对称化。值得注意的是,手性亚膦酸二酯不仅诱导了对映选择性,而且还促进了原内酰胺化。
Process for producing alpha-arylalkanoic acid esters
申请人:TAISHO PHARMACEUTICAL CO. LTD
公开号:EP0074008A2
公开(公告)日:1983-03-16
A process for producing an a-arylalkanoic acid ester represented by the general formula
wherein Ar represents an aryl group which may optionally be substituted, and R' and R2, independently from each other, represents a lower alkyl group, which comprises reacting a Grignard reagent prepared from an aryl halide of the general formula
wherein Ar is as defined above and X1 represents a halogen atom, and magnesium, with an a-haloalkanoic acid ester of the general formula
wherein R' and R2 are as defined above, and X2 represents a halogen atom, said reaction of the Grignard reagent with the a-haloalkanoic acid ester of general formula (III) being carried out in the presence of a nickel compound.