Publications scientifiques
Armelle Tontsa Tsamo
Autres affiliations : Tshwane University of Technology
Augustin Ephrem Nkengfack
Patrice Kenfack Tsobnang
Ignas Kenfack Tonlé
Acta Crystallographica Section E Crystallographic Communications
The title limonoid compound, C 26 H 28 O 5 ·0.5H 2 O ( TS3 ) [systematic name: (3a S ,3b S ,4a S ,5a S ,6 S ,7a R ,8a R ,8b S ,11a R )-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(3a H )-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 C sp 3 —C sp 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.
