Organotins as etherfication catalysts. 11. catalytic conversion of alcohols to open-chain and cyclic ethers by organotin trichlorides

1,5-Heptadien-4-ol and various 1,4- and 1,5-glycols are catalytically converted to open-chain and cyclic ethers respectively in the presence of butyltin trichloride. The dehydration of alcohols is mediated by formation of organoalkoxytin dihalides BuSn(OR)Cl2 A mechanism for the formation of these ethers is proposed. The catalytic activity of other organotins together with SnCl4 has been examined for the conversion of 1,5-pentanediol to THP; the scale of the catalytic efficiency is: MeSnCl3⩾PhSnCl3SnCl4BuSnCl3Me2SnCl2Bu2SnCl2≫ [Bu2SnCl]2O.