PRODUCTION OF RACEMIC MODIFICATION AND EPIMERIC ISOMER

PURPOSE:To obtain a racemic-erythro isomer by reacting the threo, erythro or racemic-threo-isomer of 3-(3,4-methylenedioxyphenyl)serine with piperonal in a lower alcoholic solvent and then treating the resultant product with an acid. CONSTITUTION:The threo-isomer expressed by formula I, erythro-isomer expressed by formula II or racemic-threo-isomer expressed by formula III is reacted with piperonal in a lower alcoholic solvent in the presence of an inorganic base and the resultant product is then treated with an acid to afford a racemic-erythro-isomer expressed by formula IV. Alternatively, the compound expressed by formula I, compound expressed by formula II or compound expressed by formula IV is similarly reacted with the piperonal to afford the compound expressed by formula III. The solvent is preferably a mixture solution of the lower alcoholic solvent or hydrous solvent thereof with an aprotic solvent. The compound expressed by formula III or IV is important as a synthetic intermediate for medicines and can be efficiently obtained by the afore-mentioned method.