(1β,2α,3α,7α,11α,13β)-1,3,7,11-Tetra-acet-oxy-2,13-bis-(benz-yloxy)-21-methyl-19,21-secohetisan-19-al hemi-hydrate.

In the crystal structure of the title compound, C(43)H(46)NO(13)·0.5H(2)O, the mol-ecule assumes a U-shaped conformation, the terminal benzene rings being approximately parallel and partially overlapped with each other. The mol-ecule contains eight alicyclic and heterocyclic rings. The cyclo-hexane rings adopt chair conformations, the other three six-membered carbocyclic rings form a bicyclo-[2.2.2]octane system with a boat conformation for each six-membered ring, the six-membered heterocyclic ring has a chair conformation and both of the five-membered rings have envelope conformations. The solvent water mol-ecule links with the organic mol-ecule via classic O-H⋯O and weak C-H⋯O hydrogen bonding in the crystal structure.