申请人:IMPERIAL CHEMICAL INDUSTRIES PLC
公开号:EP0304138A1
公开(公告)日:1989-02-22
The invention provides a novel process for making novel (4-phenyl-1,3-dioxan-cis-5-yl)alkenoic acids of the formula I in which Ra and Rb are independently hydrogen, alkenyl, alkyl, halogenoalkyl, pentafluorophenyl, aryl or aryl-(1-4C)alkyl; or Ra and Rb together are polymethylene; Rc is hydroxy or (1-6C)alkenesulphonamido, A is vinylene, n is 1, Y is polymethylene, and benzene ring B bear various optional substituents. The process involves the reaction of an aldehyde of formula II with an ylid to give an erythro-diol of formula III which is then cyclised to the required dioxane derivative of formula I. Also described is a novel process for making the aldehydes of formula II from the corresponding lactols of formula IIa, which are themselves obtained with the correct trans-stereochemistry by two selective reductions of a trans-phenylparaconic acid of formula V. The compounds of formula I are useful as therapeutic agents.
本发明提供了一种制造式 I 的新型(4-苯基-1,3-二氧杂环-顺式-5-基)烯酸的新工艺,其中 Ra 和 Rb 独立地为氢、烯基、烷基、卤代烷基、五氟苯基、芳基或芳基-(1-4C)烷基;或 Ra 和 Rb 共同为聚亚甲基;Rc 为羟基或(1-6C)亚烷基磺酰胺基,A 为亚乙烯基,n 为 1,Y 为聚亚甲基,苯环 B 带有各种任选取代基。该工艺包括将式 II 的醛与酰基反应,得到式 III 的赤二醇,然后将其环化为所需的式 I 的二噁烷衍生物。此外,还描述了一种从相应的式 IIa 内酯制备式 II 醛的新工艺,通过式 V 的反式苯丙二酸的两次选择性还原,以正确的反式立体化学方法制得式 IIa 内酯。