Abstract: 2-(p-Methoxyphenyl)-1, 3-dithiolan-2-yl cation (1) was isolated as a perchlorate and its reaction with water was examined kinetically in 10% aqueous acetonitrile at 30 OC. Hydration of 1 to form a 2-hydroxydithiolane intermediate 2 is rate determining at pH> 6, but the decomposition of 2 to lead to a thiolesterproduct becomes a slow step at pH< 3. At intermediate pH near the pK,(4.1) of 1, both of the steps become partially rate determining. ...