3,10-Ethano-1H,8H-furo(3,4-d)(1)benzopyran-9-acetic acid, 8-acetyl-4-(benzoyloxy)octahydro-11,12-dihydroxy-3-(methoxycarbonyl)-9-methyl-5-oxo-, (3S-(3alpha,3aalpha,4alpha,6aalpha,8alpha,9beta,10alpha,10aS*,11S*,12R*))-