24-Norchola-20,22-diene-4-carboxaldehyde, 3-(acetyloxy)-14,15:21,23-diepoxy-1,7,12,19-tetrahydroxy-4,8-dimethyl-11-oxo-, cyclic 4,19-hemiacetal, (1alpha,3alpha,4beta,5alpha,7alpha,12alpha,13alpha,14beta,15beta,17alpha)-