PURPOSE: To obtain piperidones and tetrahydropyridones useful as intermediates for pharmaceutically active compounds by reacting an appropriately substituted enamine with a particular acryloyl derivative.

CONSTITUTION: The compound of formula III [R1 is a chiral assistant; line B forms a double bond; R2 is alkylydene, aryl (alkylydene), cyclo (alkylydene) or the like; R3 is alkylthio, alkoxy, alkyl, aryl or the like; R4 is alkylthio, alkoxy, alkyl, aryl, cycloalkyl or the like; R5 is H, alkylthio, alkyl, aryl or the like; R6 is H, alkylthio, alkoxy, alkyl, aryl or the like; R7 is H, alkylthio, alkoxy, alkyl, aryl or the like] is obtained by reacting the enamine of formula I (R8 is R4; R9 is R2; when R2 is alkylydene, R9 is the corresponding alkyl) with the acryloyl derivative of formula II (X is desorption group).