摘要 |
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 (I) (where R<1> is an aliphatic group with a side chain at the 1 position, an alicyclic group, a substituted alicyclic group, a heterocyclic group, a substituted heterocyclic group, a phenyl group or a substituted phenyl group), reacting aldehydes represented by general formula (II): R<1>CHO (where R<1> is as defined above) with alkali metal salt of acetoacetic acid represented by general formula (III) (where M<+> 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) (where n is 3 or more and up to 5, m is 1 or more and up to 10, R<2> is an alkyl group having 1 to 10 carbon atoms and of straight chain or with side chains, an alkyl group substituted by alicyclic groups or phenyl groups, an alicyclic group which may be substituted by lower alkyl groups, or a phenyl group which may be substituted by lower alkyl groups, and an R<2> substitution position is at a carbon atom other than the two adjacent to N), a cyclic secondary amine represented by general formula (2) (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<3> is a lower alkyl group, its substitution position is at a carbon atom other than the two adjacent to N, and (a) is an alicyclic group or a phenyl group), or a secondary amine represented by general formula (3): CH3NHCH2R<4> (where R<4> is an aliphatic group having 5 to 17 carbon atoms and of straight chain or with side chains, an alicyclic group which may be substituted by lower alkyl groups, a phenyl group which may be substituted by lower alkyl groups, or an alkyl group substituted by phenyl groups), in a mixture solvent of water and water-insoluble organic solvent, while keeping the pH constant with mineral acid, and by adjusting the amount of water. |