| 摘要 |
PURPOSE:To simply obtain the subject compound useful as a synthetic intermediate for medicines and agricultural chemicals by treating a beta-gamma-unsaturated-o- ketoester with an organic zinc complex. CONSTITUTION:An alpha-carbonyl group of a compound of formula I (R<1> is an alkyl or an aryl; R* is an asymmetric auxiliary) is diastereoselectively alkylated using a (-) or (+)-trans-2-phenylcyclohexyl group as an asymmetric auxiliary and using an organic zinc complex as an alkylating agent in a solvent (e.g. THF) at -100 to -40 deg.C to provide the objective optically active alpha-hydroxy-2- substituted-beta,gamma-unsaturated ester of formula II (R<2> is an alkyl, an arylmethyl, vinyl or an aryl). The alkylating agent is used in an amount of 1-2mol based on 1mol of the compound of formula I. |
