[2aR-[2aa,4ß,4aß,6ß,9a(aR*,ßS*) 11a,12a,12aa,12ba]] 15(acetyloxy)-6-(benzoyloxy)-2a,3,4,4a,5,6,9,10,11,12, 12a,12b-dodecahydro-3,5,10,12-tetrahydro-2,8,11,11a tetramethyl-9 oxo-7,11-methanol-1h-cyclo-deca[3,4] benz [1,2-b] oxet -9-yl ester