Direct Oxidation of Cyclopropanated Cyclooctanes as a Synthetic Approach to Polycyclic Cyclopropyl Ketones

A series of polycyclic hydrocarbons containing cyclopropane moieties 1,2-annelated or spiro-condensed with cyclooctane ring were investigated under oxidative conditions. Four oxidizing systems (O3 on SiO2, dioxirane derived from trifluoroacetone, CrO3 and RuO4, generated in situ), were employed to evaluate and compare their reactivity and usefulness. RuO4 was found to be the best one, considering its oxidative power together with a simple preparative procedure. The conditions for specific oxidation of polycyclic hydrocarbons were found. Novel cyclooctane derivatives containing cyclopropyl carbonyl moieties were obtained.