Product analysis of the gas-phase reaction of β-caryophyllene with ozone

The semivolatile ketoaldehydes 3,3-dimethyl-y-methylene-2-(3-oxobutyl)-cyclobutanebutanal 1 and 3,3-dimethyl-γ-oxo-2-(3-oxobutyl)-cyclobutanebutanal 2 and formaldehyde have been identified as the main products of the reaction of ß-caryophyllene with ozone in the gas phase. In minor amounts 9-methylene-,t,12,12-trimethyl-5-oxabicyclo[8.2.0.0.s]dodecane 3 was also formed. Nature and yields of these carbonyl products are discussed in terms of oxidation mechanisms involving the gas-phase reaction with ozone and OH radicals.