| 摘要 |
PURPOSE:To obtain an anti-Cram form optically active hydroxy compound in high conversion and selectivity, by reacting an optically active acetal with an organotin compound in an inert solvent in the presence of a Lewis acid as a catalyst. CONSTITUTION:An acetal expressed by formula I (X is organic group; Y is <=10C hydrocarbon group; m is 0 or 1) is reacted with an organotin compound expressed by the formula R<1>-M [R<1> s Z-C=C- or CH2=CH-CH2- (Z is <=10C alkyl, cycloalkyl or allyl); M is -SnR3<2> (R<2> is 1-4C alkyl)] in an inert solvent, preferably a halogenated hydrocarbon by increasing the temperature gradually from -78 deg.C to -50 deg.C using dry ice-acetone, and an oxidizing agent is then reacted with the reaction mixture. The resultant reaction mixture is then hydrolyzed to afford the aimed compound expressed by formula II. The reaction, is preferably carried out in the presence of a Lewis acid, preferably. |
