Proton loss from an oxocarbenium moiety of ionic bicyciobutane is found to compete appreciably with the capture of the oxocarbenium by alcohol molecules. ... Vinyl ether hydrolysis provides one of the major pathways for the investigation of oxocarbenium ions.2 In practically all cases the reaction mechanism involves an irreversible proto- nation on carbon. The sole exception to this behaviour was demonstrated by the hydrolysis of 9-methoxy-2,3-didehydro- ...