1-[(1S,2S,5R,7S)-1-{2-[(3S,6S,7S,9aS)-3-hydroxy-2,2,7-trimethyloctahydro-6H-3,5a-epoxy-1-benzoxepin-6-yl]ethyl}-2,7-dimethyl-6-oxabicyclo[3.1.1]hept-7-yl]-4-methylpentan-3-one