Synthesis of cyclic ethers by cyclodehydration of 1, n-diols using heteropoly acids as catalysts. Issue 9 (26th September 2018) - Sun, Yufeng
Abstract : Heteropoly acids were used as catalysts for cyclodehydration of various 1, n -diols. Cyclodehydration of butane-1, 4-diol, pentane-1, 5-diol and hexane-1, 6-diol catalysed by H3 PW12 O40 gave tetrahydrofuran, tetrahydropyran and oxepane, respectively. Cyclodehydration of diethylene glycol, triethylene glycol, diethylene glycol monomethyl ether and polyethylene glycol 200 catalysed by H3 PW12 O40 gave 1, 4-dioxane. In particular, cyclodehydration of hexane-1, 6-diol gave an excellent yield of oxepane (80%). The selectivity exhibited by the H3 PW12 O40 catalyst was even better than that exhibited by other reported catalyst systems for similar cyclodehydration reactions.