| 摘要 |
PURPOSE:To obtain a high-purity optically active 4-hydroxy-2-cyclopentenone useful as an intermediate for perfumes and medicines besides an agricultural chemical and its intermediate inexpensively, industrially advantageously and in high yield. CONSTITUTION:An optically active cyclopentenone of formula I (R is alkyl, alkenyl or alkynyl; R at the 2-position and CH3 at the 3-position are in cis- configuration) is rearranged in the presence of a base or a catalyst, e.g. an organic tertiary amine such as triethylamine, a metallic oxide such as alumina, an inorganic base such as caustic soda or a basic buffer solution such as buffer solution of a carbonate while retaining steric configuration to industrially and advantageously obtain the objective optically active compound of formula II. The optically active compound of formula I is obtained by asymmetrically hydrolyzing a dl compound or an optically active compound of formula III (R1 is acyloxyl; R at the 2-position and CH3 at the 3-position are in cis- configuration) by using an enzyme or a microorganism. |
