Photooxidation of cedrelone, a tetranortriterpenoid from Toona ciliata

Cedrelone, a tetranortriterpenoid on photolysis by UV light yields a true p hotooxidation product 3 [14 beta ,15 beta ,22 beta ,23 beta -diepoxy-6-hydr oxy-1,5,20(22)-meliatriene-2,7,21-trione] whose structure is well establish ed by NMR studies and confirmed by X-ray crystallography, along with produc t 4 [14 beta ,15 beta -epoxy-6,23-dihydroxy-1,5,20(22)-meliatriene-2,7,21-t rione]. Addition of rose bengal increases the rate of photooxidation wherea s DABCO decreases rate of photolysis proving the involvement of singlet oxy gen in the photooxygenation. Both the photoproducts exhibited antifeedant a ctivity.