Oxidative fragmentation of 1-aryl-1-cycloalkenes using cerium(IV) ammonium nitrate (CAN): some novel observations

1-Phenyl-1-cycloalkenes undergo oxidative fragmentation in presence of CAN in methanol, affording 1,n-dicarbonyl compounds as the major products along with 1,2-dimethoxycycloalkanes. The reaction under deoxygenated conditions afforded the latter in good yields. In the presence of azide ion, fragmentation leading to the corresponding cyanoketones was observed whereas with sulfinate only the 1-methoxy-2-sulfonyl cycloalkanes were formed.