申请人:SUMITOMO CHEMICAL COMPANY, LIMITED
公开号:EP0153653A1
公开(公告)日:1985-09-04
A process for preparing an optically active 2-substituted or unsubstituted-4-hydroxy-2-cyclopentenone of the formula.
wherein R is a hydrogen atom, an allyl group or a propargyl group, which comprises reacting the corresponding 2- substituted or unsubstituted-4-hydroxy-2-cyclopentenone of the formula:
wherein R is defined above with a lactone chosen from (1R,5S)-6,6-Edimethyl-4-hydroxy-3-oxabicycto(3.1.0]hexan-2- one or (1S,5R)-6,6-dimethyl-4-hydroxy-3-oxabicyclo[3.1.0]-hexan-2-one in a molar ratio of 1.5 - 2 : 1 in the presence of p-toluenesulfonic acid or benzenesulfonic acid in the coexistence of an organic solvent under elimination of water as an azeotropic mixture with the organic solvent to obtain a reaction mixture comprising (1R,5S)-6,6-dimethyl-3-oxa-4(R)-[1(R)-4-oxo-2-substituted or unsubstituted-2-cyclo- pentenyloxy]bicyclo[3.1.0]hexan-2-one or (1S,5R)-6,6-dimethyl-3-oxa-4(S)-[1(S)-4-oxo-2-substituted or unsubstituted-2-cyclopentenyloxy]bicyclo[3.1.0]hexan-2-one of the formula:
wherein R is as defined above, of which either one isomer is contained in a considerably larger amount than the other isomer, separating the isomer having the larger content from the reaction mixture and hydrolyzing the separated isomer to give the optically active 2-substituted or unsubstituted-4-hydroxy-2-cyclopentenone.
一种制备具有光学活性的式 2-取代或未取代-4-羟基-2-环戊烯酮的工艺。
其中 R 为氢原子、烯丙基或丙炔基,该工艺包括将相应的式 2-取代或未取代-4-羟基-2-环戊烯酮与选自(1R,5S)、(1R,5S)和(1R,5S)的内酯反应:
其中 R 如上定义,与选自 (1R,5S)-6,6-二甲基-4-羟基-3-氧杂双环[3.1.0]己烷-2-酮或 (1S,5R)-6,6-二甲基-4-羟基-3-氧杂双环[3.1.0]己烷-2-酮的内酯在摩尔比为 1.5 - 2 : 1 的对甲苯磺酸或苯磺酸存在下,在有机溶剂的共沸混合物中消除水,得到包含 (1R,5S)-6,6-二甲基-3-氧杂-4(R)-[1(R)-4-氧代-2-取代或未取代-2-环戊烯氧基]双环[3.1.0]己-2-酮或式(1S,5R)-6,6-二甲基-3-氧杂-4(S)-[1(S)-4-氧代-2-取代或未取代-2-环戊烯氧基]双环[3.1.0]己-2-酮:
其中 R 如上文所定义,其中一种异构体的含量大大高于另一种异构体,从反应混合物中分离出含量较高的异构体,水解分离出的异构体,得到光学活性的 2-取代或未取代-4-羟基-2-环戊烯酮。