Oxidation of some alkoxy-cycloheptatriene derivatives: unusual formation of furan and furanoids from cycloheptatrienes

The oxidation of some alkoxy tropone and tropone ketal derivatives with singlet oxygen and m-chloroperbenzoic acid was investigated. In most cases furan and furanoid derivatives were isolated. The structures of the formed products were determined by means of spectral data and the formation mechanism of these unusual products is discussed.