ent-Kaur-16-en-19-al

Abstract

Key indicators: single-crystal X-ray study; T = 100 K; mean (C-C) = 0.002 Å; R factor = 0.035; wR factor = 0.097; data-to-parameter ratio = 14.1.The title ent-kaurane diterpene compound, C 20 H 30 O, was isolated from the roots of Bruguiera cylindrica (Rhizophoraceae), a mangrove plant. The molecule contains a fused fourring system, with the three cyclohexane rings in standard chair conformations and the cyclopentane ring adopting an envelope conformation. The aldehyde is bisectionally attached to the cyclohexane ring. The methylene group is coplanar with the attached cyclopentane ring. In the crystal structure, molecules are packed by van der Waals interactions. Related literatureFor the values of bond lengths, see Allen et al. (1987). For literature on ring conformations, see Cremer & Pople (1975). For further details of ent-kaurane diterpenes and their bioactive properties, see, for example: Karle (1972); Mü ller et al. (2003); Salae et al. (2007). Experimental Crystal data C 20 H 30 O M r = 286.44 Orthorhombic, P2 1 2 1 2 1 a = 6.3126 (2) Å b = 11.2823 (4) Å c = 22.8044 (7) Å V = 1624.14 (9) Å 3 Z = 4 Mo K radiation = 0.07 mm À1 T = 100.0 (1) K 0.56 Â 0.40 Â 0.13 mm Data collection Bruker SMART APEXII CCD area-detector diffractometer Absorption correction: multi-scan (SADABS; Bruker, 2005) T min = 0.952, T max = 0.991 20475 measured reflections 2709 independent reflections 2571 reflections with I > 2(I) R int = 0.029 Refinement R[F 2 > 2(F 2 )] = 0.035 wR(F 2 ) = 0.097 S = 1.07 2709 reflections 192 parameters H-atom parameters constrained Á max = 0.31 e Å À3 Á min = À0.17 e Å À3 Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 1998); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003).