Improvements in or relating to therapeutic substances

摘要

A water-soluble stable ether of vitamin A of the formula in which vitamin A alcohol is represented by V-CH2OH and n is 2 or 3 is obtained by etherifying vitamin A alcohol in the presence of an acid binding agent with a polyhydroxy-alkyl halide in which the hydroxyl groups have been suitably protected, e.g. by acylation or conversion into an isopropylidine derivative, and subsequently removing the protecting groups from the product obtained. Preferably the reaction is effected in quinoline in the presence of silver carbonate. Detailed examples are given.