Sodium periodate is a better reagent than sodium bismuthate, manganese dioxide, or lead tetraacetate for the cleavage of unsaturated a-ketols and affords w-oxo-a, O-unsaturated acids in good yield. The combination of this cleavage reaction and a rhodium (1)-mediated decarbonylation of w-oxo-a,#?-unsaturated esters derived from polycyclic systems provided an enantioselective synthesis of cyclic systems bearing contiguous quaternary centers ...
