1,5-Dimethyl-hexa-1,5-dienylene compounds, and especially Vitamin A and derivatives thereof, are made by desuphonylating with a basic reagent a sulphone of the formula: ##STR1## in which the sulphonyl group --SO.sub.2 R replaces a hydrogen atom on carbon atom (a) or (b), R represents a phenyl or napthyl group, A is 2-(2,6,6-trimethylcyclohex-1-enyl)ethenyl, and Q is --CH.sub.2 OH or an ether or ester thereof, CHO, or an acetal group.
1,5-二甲基己-1,5-二烯基化合物,特别是
维生素A及其衍
生物,通过使用碱性试剂去
硫酰基化合物的方法制备,该
硫酰基化合物的
化学式为:##STR1## 其中
硫酰基--SO.sub.2 R取代碳原子(a)或(b)上的氢原子,R代表苯基或
萘基,A为2-(2,6,6-三甲基
环己-1-烯基)
乙烯基,Q为--CH.sub.2 OH或其醚或酯,CHO或
缩醛基团。