(4aS,10aS)-7-Hydroxy-8-isopropyl-1,1,4a-trimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthrene: a new diterpenoid compound

Abstract

The new title diterpenoid compound, C20H30O, is a natural product isolated from Tetra­clinis articulata wood via chloro­form extraction. The asymmetric unit contains four mol­ecules with the same S,S configuration, deduced from the chemical synthesis. Indeed, an overlay analysis, calculated using structure-matching software, shows that the four mol­ecules can be superimposed. The central ring has a half-chair conformation, whereas the saturated ring displays a chair conformation.

(4bS,8aS)-1-Isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a,9,10-octahydrophenanthren-2-yl acetate

“…The central unsaturated ring has an half chair conformation with puckering parameters: Q = 0.531 (2) Å, θ= 50.4 (2)° and φ= 120.1 (4)° (Cremer & Pople, 1975), whereas the second insaturated six-membered ring displays a chair conformation with puckering parameters: Q = 0.535 (3) Å, θ= 173.2 (3) (2)° and φ= 289 (2)°. Similar conformation for the three fused rings has been reported previously with hydroxyl substituent in place of the acetate in the title compound (Zeroual et al, 2008) and with either an hydroxyl or a methoxy substituent on the central ring (Pettit et al, 2004).…”

“…For biological properties of totarol, see: Barrero et al (2003); Bernabeu et al (2002); Haraguchi et al (1996); Marcos et al (2003); Tacon et al (2012). For related structures, see: Zeroual et al (2008); Pettit et al (2004). For structural discussion, see: Cremer & Pople (1975); Flack (1983); Flack & Bernardinelli (2000); Spek (2009).…”

(4bS,8aS)-1-Isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a,9,10-octahydrophenanthren-2-yl benzoate

“…(3) Å, θ= 48.6 (3)° and φ= 128.9 (4)° (Cremer & Pople, 1975), whereas the second saturated six-membered ring, (III), displays a chair conformation with puckering parameters Q = 0.546 (3) Å, θ= 175.8 (3)° and φ= 301 (4)°. Similar conformation for the three fused rings has been reported previously with hydroxyl substituent or methyl acetate in place of the benzoate of the title compound (Zeroual et al, 2008;Oubabi et al, 2014), and with either an hydroxyl or a methoxy substituent on the central ring (Pettit et al, 2004).…”

“…For conformational analysis and absolute configuration determination, see: Cremer & Pople (1975); Flack (1983); Flack & Bernardinelli (2000); Parsons et al (2013); Spek (2009). For related structures, see: Zeroual et al (2008); Oubabi et al (2014); Pettit et al (2004). Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR97 (Altomare et al, 1999); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL2013.…”

Crystal structure of (4bS,8aR)-1-isopropyl-4b,8,8-trimethyl-7-oxo-4b,7,8,8a,9,10-hexahydrophenanthren-2-yl acetate

“…One with a similar conformation has a hydroxyl substituent in place of the acetate in the title compound (Benharref et al, 2011), and three others have a methoxy group in position 4b and carbaldehyde/benzenesulfonohydrazide (Vo et al, 2008) or biphenylsulfonyl (Gu & You, 2011) in position 9 ( Fig. 4b), while six entries (Oubabi et al, 2014a,b;Zeroual et al, 2007Zeroual et al, , 2008Cutfield et al, 1974;Pettit et al, 2004) have 1-isopropyl-4b,8,8-trimethyl substituents ( Fig. 4c).…”