| 摘要 |
PURPOSE:To produce a coumarin compound from 3,4-dihydrocoumarins at a low catalyst cost by using a catalyst having high selectivity. CONSTITUTION:A coumarin compound of formula II is produced by the dehydrogenation of a 3,4-dihydrocoumarin compound of formula I (R1 to R4 are H, methyl or ethyl provided that at least two of the groups are H). The dehydrogenation reaction is carried out by using a palladium catalyst used in the cyclizing dehydrogenation reaction for producing the 3,4-dihydrocoumarin compound of formula II from a 3-(2-cyclohexanoyl)propionic acid ester of formula III (R5 is 1-4C alkyl). |
