24-Norchola-5,14,20,22-tetraeno[6,5,4-bc]furan-1,3,7,12-tetrol,21,23-epoxy-4,5,5',6-tetrahydro-4,8-dimethyl-, 3,12-diacetate1-(2-methyl-2-butenoate), [1a(E),3a,4b,5a,6b,7a,12a,13a,17a]-

24-Norchola-5,14,20,22-tetraeno[6,5,4-bc]furan-1,3,7,12-tetrol,21,23-epoxy-4,5,5',6-tetrahydro-4,8-dimethyl-, 3,12-diacetate1-(2-methyl-2-butenoate), [1a(E),3a,4b,5a,6b,7a,12a,13a,17a]- ·