3,13-Ethano-1H,10H-furo(3,4-c)furo(2',3':6,7)naphtho(2,3-b)pyran-3(3aH)-carboxylic acid, 4-(acetyloxy)-4,5,6a,7,7a,8,12a,13-octahydro-14,15-dihydroxy-8,12a-dimethyl-5,10-dioxo-, methyl ester, (3S-(3alpha,3aalpha,4alpha,6aalpha,7abeta,8beta,12a))