Chlorinative rearrangements of bicyclic and monocyclic carbinols via the action of bleach and vinegar

Investigation into a NaOCl/AcOH induced exo-olefin insertion/ring expansion of bicyclic vinyl carbinols led to a systematic study of this rearrangement. This ring expansion/elimination reaction proceeds first through a chlorinative ring enlargement to form a beta-chloroketone. Elimination of HCl follows to produce exocyclic enones in good yields and regioselectivity. Interestingly in the bicyclic [2.2.2] chlorinative ring expansions, each diastereomeric starting carbinol rearranges stereospecifically to produce bicyclic beta-chloroketones. Other issues addressed include substrate scope, as well as the chemo-, regio-, and diastereoselectivity of these chlorinative ring expansions. Subsequent experimentation with other non-vinylogous carbinols led to the observation of a number of other chlorinative rearrangements. The information gleaned from this methodology is an important addition to the database of rearrangements in bicyclic and monocyclic carbinols.