Acid-catalyzed hydrolysis of bridged bi- and tricyclic compounds. XXXVII. Kinetics and mechanisms of 1- and 3-acetoxynortricyclanes

The disappearance of 3- and 1-acetoxynortricyclanes (1 and 2) in aqueous pe rchloric acid was followed by capillary gas chromatography at different tem peratures and acid concentrations. According to the activation parameters, solvent deuterium isotope effects and parameters of excess acidity equation s, the A(AC)2 ester hydrolysis with two water molecules in the transition s tate is dominant at the lower acid concentrations studied (1-5.5 M HClO4) a nd the Ad(E)2 hydration of the cyclopropane ring is dominant at higher acid concentrations (6-8 M HClO4) at 298 K, 3-Nortricyclanol (3) is formed via hydrolysis from 1, whose hydration products were not analyzed. 2-Norbornano ne (3) is formed via both hydrolysis and hydration from 2. Copyright (C) 20 00 John Wiley & Sons, Ltd.