The ozonation of four bornene derivatives, prepared from (R)-(+)-pulegone, which possess a particularly hindered double bond, led to the formation of unexpected products depending on the nature of the solvent. The formation of the corresponding epoxides, ketones with the same skeleton, various lactones and even an allyl alcohol and an allyl chloride (allylic functionalisation) was observed. In two
In the course of the ozonolysis of the bicyclo[2.2.1]heptene anhydride 1, the three bis-lactones 3–5 have been obtained (the structures were confirmed by X-ray crystallographic analysis).
of bicyclo[2.2.1]heptene derivatives 6 and 7 obtained from (R)-(+)-pulegone through the cyclopentadiene 5 and its Diels–Alderreaction with maleic anhydride. The ozonolysis of the tricyclic diol 7 led to the ketone 8 with the same skeleton while the anhydride 6 gave rise to the epoxide 10 and the bis-lactone 11. The structure of 8, 10 and 11 are confirmed by X-ray analysis. These unexpected results are