Low-temperature pyrolysis. II. An isotope study of the pyrolysis of the hydrogen phthalate ester of trans-1,2-dimethylcyclohexanol

The hydrogen phthalate ester of trans-l,2-dimethylcyclohexanol was prepared by using phthalic anhydride enriched in 18O. The ester was partially decomposed at 128°. An observed enrichment of 18O in the alcohol portion of the undecomposed ester supports an earlier postulate that an ion pair is involved in the thermal decomposition of this sterically hindered ester.