| 摘要 |
PROBLEM TO BE SOLVED: To easily and safely produce the subject compound useful as various synthetic raw materials or intermediates, perfumery, etc., on an industrial scale in high yield at a low cost by carrying out condensation and dehydration of a specific unsaturated aldehyde with a specific ketone in the presence of a condensation agent. SOLUTION: The objective compound of formula III [e.g. (3E,5E)-octadien-2- one] is produced by the condensation and dehydration of (A) anα,β-unsaturated aldehyde of formula I (R<1> is H or the like) [e.g. (2E)-pentenal] with (B) a ketone of formula II (R<2> is H or the like; R<3> is methyl or the like) (e.g. acetone) in the presence of (C) a condensation agent, preferably an aqueous solution of an alkaline base (e.g. sodium hydroxide), preferably using 5-10 equivalent of the component B and 0.1-0.2 equivalent of the component C based on 1 mol of the component A preferably at 0-40 deg.C for 1-4 hr. In the above reaction, preferably a mixture of the components A and B is added to the component C by dropping, or the like.
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