14-Hydroxy-8,14-secogammacera-7-ene- 3,21-dione from the bark of Lansium domesticum Corr. Unang Supratman, a Tri Mayanti, a Khalijah Awang, b Mat Ropi Mukhtar b and Seik Weng Ng b * a Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padjadjaran University, Jatinangor 45363, Indonesia, and b Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia Correspondence e-mail: seikweng@um.edu.my Received 2 June 2010; accepted 3 June 2010 Key indicators: single-crystal X-ray study; T = 100 K; mean (C–C) = 0.003 A ˚ ; R factor = 0.039; wR factor = 0.098; data-to-parameter ratio = 11.2. In the title compound (kokosanolide B), C 30 H 48 O 3 , the hexahydro- and octahydronaphthalen-2-one ring systems are connected through an ethylene fragment, with a C—CH 2 — CH 2 —C torsion angle of 176.2 (2) . The cyclohexene ring adopts a half-chair conformation, while the other six- membered rings adopt distorted chair conformations. In the crystal, adjacent molecules are linked into a zigzag chain along the b axis by O—HO hydrogen bonds involving the hydroxy and carbonyl groups. Related literature For a related compound from the same species, see: Tjokro- negero et al. (2009). For kokosanolide A, see: Mayanti et al. (2009). Experimental Crystal data C 30 H 48 O 3 M r = 456.68 Orthorhombic, P2 1 2 1 2 1 a = 11.8841 (11) A ˚ b = 14.8301 (13) A ˚ c = 15.2755 (13) A ˚ V = 2692.2 (4) A ˚ 3 Z =4 Mo K radiation = 0.07 mm 1 T = 100 K 0.20 0.10 0.05 mm Data collection Bruker SMART APEXII diffractometer 26171 measured reflections 3469 independent reflections 3033 reflections with I >2(I) R int = 0.067 Refinement R[F 2 >2(F 2 )] = 0.039 wR(F 2 ) = 0.098 S = 1.01 3469 reflections 310 parameters 1 restraint H atoms treated by a mixture of independent and constrained refinement Á max = 0.25 e A ˚ 3 Á min = 0.20 e A ˚ 3 Table 1 Hydrogen-bond geometry (A ˚ , ). D—HA D—H HA DA D—HA O2—H2O3 i 0.84 (1) 2.15 (1) 2.974 (2) 167 (3) Symmetry code: (i) x þ 2; y þ 1 2 ; z þ 3 2 . Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X- SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010). This work was supported by the Directorate of Higher Education, Indonesia, the University of Padjadjaran (I- MHERE Project) and the University of Malaya (UMRG RG011/09BIO). Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CI5095). References Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. Bruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Mayanti, T., Supratman, U., Mukhtar, M. R., Awang, K. & Ng, S. W. (2009). Acta Cryst. E65, o750. Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Tjokronegero, R., Mayanti, T., Supratman, U., Mukhtar, M. R. & Ng, S. W. (2009). Acta Cryst. E65, o1448. Westrip, S. P. (2010). J. Appl. Cryst. 43. Submitted. organic compounds Acta Cryst. (2010). E66, o1621 doi:10.1107/S1600536810021136 Supratman et al. o1621 Acta Crystallographica Section E Structure Reports Online ISSN 1600-5368