Abstract: The present invention relates to a method for the synthesis of .alpha., .beta.-unsaturated ketones which comprises, in the method for the synthesis of .alpha., .beta.-unsaturated ketones represented by general formula ##STR1## reacting aldehydes represented by general formulaR.sup.1 CHO(where R.sup.1 is as defined above) with alkali metal salt of acetoacetic acid represented by general formula ##STR2## (where M.sup..sym. is an alkali metal ion), in the presence as a catalyst of 3-azabicyclo[3,2,2]nonane, a cyclic secondary amine represented by general formula (1) ##STR3## a cyclic secondary amine represented by general formula (2) ##STR4## (where, l is 1 or more and up to 6, a ring with N is a 6-membered, 7-membered or 8-membered ring, the two neighbors of N are methylene, R.sup.3 is a lower alkyl group, its substitution position is at a carbon atom other than two those adjacent to N, and ##STR5## is an alicyclic group or a phenol group), or a secondary amine represented by general formula (3)CH.sub.3 NHCH.

Abstract: The present invention relates to a method for the preparation of .alpha., .beta.-unsaturated ketones represented by general formula (II) ##STR1## (where R is a heterocyclic group with nitrogen atom in the ring or a phenyl group with electron donative substituents) which comprises reacting aldehydes represented by general formula (I)RCHO (I)(where R is a s defined above) with acetone, in the presence as a catalyst of one or tow or more compounds selected from the group consisting of perhydroisoindole and pyrrolidine which may have substituents, in a water solvent, at 20.degree. C. to 40.degree. C., and then reacting at the reflux temperature.The compound (II) is extremely important as an intermediate for pharmaceuticals and agricultural chemicals.