| 摘要 |
PURPOSE:To obtain 3-methyl-4-hydroxy-2-cyclopentenone, etc., by hydrolyzing 2,5-dimethoxy-2,5-dimethyldihydrofuran, etc., and bringing the resultant 3-hexene- 2,5-dione, etc. into contact with a basic catalyst. CONSTITUTION:A compound of formulaI(R is H, ethyl, propyl or allyl) is hydrolyzed in the presence of an acidic catalyst, e.g. acidic anion exchange resin or sulfuric acid, at 10-50 deg.C to give a compound of formula II, which is then brought into contact with a basic catalyst, e.g. an alkali metallic hydroxide or amine, at 10-150 deg.C to afford a compound of formula III. The series of the reactions is preferably carried out in a solvent, e.g. water, alcohol, ether or aromatic hydrocarbon, and water in an amount to ionize the catalyst is required in the solvent. EFFECT:The aimed compound is obtained easily in high purity and yield from an easily available starting material under mild conditions without using a special or toxic reagent. |
