Regioselective synthesis of substituted tropones and azulenes using anodic oxidation of cycloheptatriene systems as the key reaction
摘要:
Regioselective synthesis of di- and trisubstituted tropones has been attained by utilizing anodic oxidation of cycloheptatriene systems as the key reaction. This anodic oxidation has also been found to be useful for the regioselective synthesis of mono- and disubstituted azulenes.
The preparation of 4-alkyl (or aryl) tropones has easily been accomplished by the anodic oxidation of 1-methoxy-4-alkyl (or aryl) cycloheptatrienes which were synthesized by the regioselective addition of alkyl or aryl lithium to 3-position of 7,7-dimethoxyeycloheptatriene followed by the thermal 1,5-hydrogen shift of the resulting 3-methoxy-7-alkyl (or aryl) cycloheptatrienes.