(1aR,2E,4aR,6S,7aR,8E,11aS)-1a,4a,5,6,7a,10,11,11a-Octahydro-4a-hydroxy-1,1,3,6,9-pentamethyl-1H-cyclopenta[a]cyclopropa[f]cycloundecene-4,7-dione