The Ring-opening Reaction of 1, 2-Epithiodecane with Mixtures of t-Butyl Alcohol and Other Alcohols

Abstract

The ring-opening reaction of 1, 2-epithiodecane with a mixture of t-butyl alcohol and ethanol in the presence of sulfuric acid gave a mixture of 1-ethoxy-2-decanethiol (1), 2-ethoxy-1-decanethiol (2), 1-ethoxy-2- (t-butylthio) decane (3), 2-ethoxy-1- (t-butylthio) decane (4), 1-mercapto-2-decanol (5), and 1-t-butylthio-2-decanol (6). The product distribution varied with reaction time, amounts of sulfuric acid, and molar ratio of t-butyl alcohol to ethanol, the ratio of (4) to total products increased with longer reaction time or larger amounts of sulfuric acid.Among these products, it was proved that (5) and (6) were formed via the reaction of 1, 2-epithiodecane with t-butyl alcohol. The formation of (3), (4), and (6) are reasonably explained in terms of intermediacy of the episulfonium (7) which is formed by the attack of t-butyl cation to 1, 2-epithiodecane.The reaction of 1, 2-epithiodecane with a mixture of t-butyl alcohol and methanol, 1-propanol or 2-propanol in the presence of sulfuric acid gave the products corresponding to (4), and the order of these yields was methanol>ethanol>1-propanol>2-propanol.