| 摘要 |
PURPOSE:To obtain the title compound useful as an intermediate for synthesis of pilocarpine hydrochloride, a remedy for glaucoma, industrially and advantageously by treating a dihydrofuranone derivative with an acid catalyst such as a sulfonic acid derivative and then reacting the treated substance with a lower alcohol. CONSTITUTION:A dihydrofuranone derivative shown by formula I (R1 to R3 are H or lower alkyl) is treated with an acid catalyst selected from a sulfonic acid derivative shown by the formula R<4>SO3H [R<4> is H, (halo-substituted) lower alkyl or (substituted) phenyl] and a sulfonic group containing resin and then reacted with an alcohol shown by the formula R<5>OH (R<5> is lower alkyl) to give the objective compound shown by formula II. |
