4,6-Methanocyclobuta[cd]cyclopropa[3,4]benzo[1,2-a]pentalen-5(1H)-one,dodecahydro-1a,2,3a,4-tetrahydroxy-6-(hydroxymethyl)-1,1,3,5a-tetramethyl-,(1aR,2S,3S,3aR,3bS,4R,5aR,5bS,6S,6aR,6bR,6cS)-rel- (9CI)