Surprising results during the re-investigation of the formation and decomposition of triptene ozonide

Revision of the ozonolysis of triptene (= 2,3,3-trimethylbut-1-ene; 1) reve aled that molecular oxygen of an applied ozone/oxygen gas mixture participa tes as well in the cleavage of the C=C bond as in the ozonide formation. Oz one-to-olefin stoichiometry varies in the range of 0.64-0.95:1 in terms of complete olefin consumption, depending on solvents, on reaction temperature , and on reaction conditions. Thermal decomposition of distilled monomeric triptene ozonide (2) does not lead to 3,G-di(tert-butyl)-3,6-dimethyl-1,2,4 ,5-tetroxane (5), which is formed by formaldehyde extrusion from an unstabl e oligomeric (probably dimeric) triptene ozonide 2'. Acid-catalyzed decompo sition of 2 exclusively yields pinacolone (7) and formic acid (9).