Intramolecular Nucleophilic Catalysis by the Neighboring Hydroxyl Group in Acid-Catalyzed Benzenesulfonamide Hydrolysis

Article abstract of DOI:10.1021/jo00193a001

The reactivity towards the neighboring hydroxyl group of two N,N-dialkylbenzenesulfonamide systems 1 and 2 is extraordinarily sensitive to structure.In the presence of o-CH2OH, the SO2NMe2 group is stable almost indefinitely in 1 M HCl, whereas the corresponding compound with o-CMe2OH cyclizes to the sultone under the same conditions with a half-life of around 20 min.When the sulfonamide group is constrained in a five-membered ring its cleavage must be followed by the stopped-flow technique.These very large variations in reactivity are interpreted primarily in termsof ground-state strain, which is partially relieved in the transition state for cyclization.