4-Hydroxy-3-methoxybenzeneacetic acid (2S,3aR,3bS,6aR,9aR,9bR,10R,11aR)-2-benzyl-6a-hydroxy-8,10-dimethyl-11a-(1-methylethenyl)-7-oxo-3a,3b,6,6a,9a,10,11,11a-octahydro-7H-2,9b-epoxyazuleno[5,4-e]-1,3-benzodioxol-5-ylmethyl ester