Crystal structure of limonoid TS3, isolated from Trichilia rubescens

The title limonoid compound, C(26)H(28)O(5)·0.5H(2)O (TS3) [systematic name: (3aS,3bS,4aS,5aS,6S,7aR,8aR,8bS,11aR)-6-(furan-3-yl)-3a,5a,8b,11a-tetra­methyl-3a,4a,5,5a,6,7,7a,8b,11,11a-deca­hydro­oxireno[2′,3′:4b,5]oxireno[2′′,3′′:2′,3′]cyclo­penta­[1′,2′:7,8]phenanthro[10,1-bc]furan-3(3aH)-one hemihydrate], crystallizes with two independent mol­ecules (1 and 2) in the asymmetric unit and one water mol­ecule. TS3 is composed of three six-membered rings (A, C and D), three five-membered rings (B, E and F) and two epoxide rings. A group of five fused rings (A–E) is bonded to a furan ring (F) with a Csp (3)—Csp (2) bond [1.500 (3) Å in mol­ecule 1 and 1.499 (3) Å in mol­ecule 2]. The absolute structures of the mol­ecules in the crystal were determined by resonant scattering; Flack parameter = 0.05 (5). In the crystal, the individual mol­ecules stack in columns along the b-axis direction. The water mol­ecule bridges mol­ecules 1 and 2 via O(water)—H⋯O and C—H⋯O(water) hydrogen bonds. Together with further C—H⋯O hydrogen bonds, linking mol­ecules 1 and 2, the columns are linked to form slabs parallel to the ab plane. Within each column, mol­ecules are also linked via C—H⋯π inter­actions involving the five-membered furan (F) rings.