New derivatives of 8-dehydro-vitamin A obtained by vinylating or ethynylating and subsequently partially hydrogenating, 1-[3-methyl-octa-1-yne,3,5,-dien-7-on-1-yl]-2,6-dimethyl-cyclohex-1-ene or its 5- and/or 6-methyl derivatives, converting the resulting alcohols to the corresponding derivatives of 8-dehydro-vitamin A halides by reacting with thionyl chloride or phosgene, and if required converting the resulting alcohols or halides to the corresponding trialkylphosphonium salts or triarylphosphonium salts, or reacting the 8-dehydro-vitamin A halide derivatives with alkali metal salts or alkaline earth metal salts or anhydrides of lower carboxylic acids. The new compounds can be partially hydrogenated to the corresponding polyene compounds, in which case the cis-trans isomer mixtures first obtained can be rearranged in the conventional manner to the physiologically active all-trans compounds. Accordingly, the process provides a method for the total synthesis of vitamin A, and of other compounds of the carotinoid series, which is independent of the Wittig ylide synthesis.
通过
乙烯化或
乙炔化获得的8-去氢
维生素A的新衍
生物,并随后部分氢化,1-[3-甲基-辛-1-炔烯-3,5-二烯-7-酮-1-基]-2,6-二甲基环己-1-烯或其5-和/或6-甲基衍
生物,将得到的醇转化为相应的8-去氢
维生素A卤化物衍
生物,通过与亚砜
氯或
光气反应,如果需要,将得到的醇或卤化物转化为相应的三烷基
磷酸盐或三芳基
磷酸盐,或将8-去氢
维生素A卤化物衍
生物与碱
金属盐或碱土
金属盐或较低
羧酸的酐反应。新化合物可以部分氢化为相应的聚烯烃化合物,在这种情况下,最初得到的顺反异构体混合物可以按传统方法重排为生理活性的全反异构体化合物。因此,该过程提供了一种
维生素A和其他类
胡萝卜素系列化合物的全合成方法,独立于Wittig叶立德合成。