Unusual Rearrangements in Cyclohex-3-ene-1-carboxamide Derivatives: Pathway to Bicyclic Lactones

The synthesis of new bicyclic lactone derivatives was carried out starting from 2-methyl/phenyl-3a,4,7,7a-tetrahydro-1H-isoindole-1,3(2H)-dione. 6-(Hydroxymethyl)-N-methyl/phenylcyclohex-3-ene-1-carboxamide derivatives were obtained from the reduction of tetrahydro-1H-isoindole-1,3(2H)-diones with NaBH4. Bromination and epoxidation reactions of both compounds were examined, and the structures of the resulting products were determined by spectroscopic methods. Substituted bicyclic lactone compounds, which are interesting rearrangement products in both bromination and epoxidation reactions, were obtained. In particular, hydroxymethyl (-CH2OH) and amide (-CONHR) groups attached to the cyclohexene ring in the bromination and epoxidation reactions were found to be effective in product formation. As a result, a new and applicable method was developed for the synthesis of bicyclic lactone derivatives.