| 摘要 |
PROBLEM TO BE SOLVED: To easily produce an acetal even in the case where an unstable synthesis is included or water exists in a reaction system by using a specific catalyst in the reaction of an aldehyde or a ketone with an alcohol. SOLUTION: An acetal of formula II or formula III (R3 is a monovalent 1-20C hydrocarbon; R4 is an alkylene) is produced by reacting an aldehyde or a ketone of formula I (R1 and R2 are each H or a monovalent 1-20C hydrocarbon, or R1 and R2 together form an alkylene) with an alcohol using at least one compound selected from the group consisting of stannous chloride dihydrate, cerium chloride hexahydrate and bismuth chloride as a catalyst. The use of the catalyst is preferably in such an amount that the concentration of the catalyst becomes 0.1ppm to 2%, especially in the range of about 1-500ppm based on the reaction liquid. Water is produced in the reaction as a byproduct, and accordingly it is preferable to remove water to suppress the hydrolysis of the acetal. Various kinds of acetals can be produced by the process. Isovaleral dimethallyl acetal is a new compound which has been synthesized by the process, and the compound itself is useful as a component of a perfumery. |
