- Process for producing octahydrocoumarin or derivative thereof
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For producing octahydrocoumarin or a derivative thereof represented by: wherein R1 to R4 each represents hydrogen or C1-5 alkyl (a) a 3-(2-oxocyclohexyl)propionic acid ester or derivative thereof represented by: where R1 to R4 are as defined above and R5 represents C1-5 alkyl, is reduced at 0-25°C using hydrogen in the presence of a catalyst (e.g. Ru, Rh, Pd, Ph) and optionally a solvent and/or an acid or alkali, thereby to convert the compound of formula (1) to a 3-(2-hydroxycyclohexyl)propionic acid ester or derivative thereof represented by: wherein R1 to R5 are as above and optionally removing e.g. by distillation the alcohol formed; (b) the compound of formula (2) is cyclized at 0-300°C preferably with an acid or alkali as catalyst and with continuous removal of reaction products or alcohol thereby to convert the compound of formula (2) to octahydrocoumarin or a derivative with elimination of an alcohol. The product (3) is usually a mixture of cis- and trans- isomers and is obtained in good yield. It is useful in perfumes.
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