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ABSTRACT: The title compound, C20H26O2, was isolated from a chloroform extract of Tetraclinis articulata wood. The molecule contains three fused rings which exhibit different conformations. The non-aromatic oxo-substituted ring has a screw-boat conformation, while the central ring has a half-chair conformation. In the crystal, molecules are linked to each other by intermolecular O—H...O hydrogen bonds involving the carbonyl and hydroxy groups.
Acta Crystallographica Section E. 01/2011;
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ABSTRACT: The title compound, C21H26O, was semisynthesized from isocostic acid, isolated from the aerial part of Inula Viscosa (L) Aiton [or Dittrichia Viscosa (L) Greuter]. The cyclohexene ring has a half-chair conformation, whereas the cyclohexane ring displays a chair conformation.
Acta Crystallographica Section E. 01/2011;
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ABSTRACT: The title compound, C17H22O2, was semi-synthesized from a mixture of α-atlantone (Z) and α-atlantone (E), which were isolated from the essential oil of the Atlas cedar (cedrus atlantica). The molecule consists of fused six- and seven-membered rings. The seven-membered ring is in a screw-boat conformation.
Acta Crystallographica Section E. 01/2011;
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ABSTRACT: The title compound, C23H31NO, was semisynthesized from isocostic acid, isolated from the aerial part of Inula Viscosa (L) Aiton [or Dittrichia Viscosa (L) Greuter]. The cyclohexene ring has a half-chair conformation, whereas the cyclohexane ring displays a chair conformation. The dihedral angle between the latter ring and its substituent is 83.6 (7)°.
Acta Crystallographica Section E. 01/2011;
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ABSTRACT: The title compound, C15H20O5 (systematic name: 5-hydroxy-1a,4a-dimethyl-7-methyleneperhydrodioxireno[5,6:9,10]cyclodeca[1,2-b]furan-8-one), was obtained by the reaction of 3-chloroperbenzoic acid with 9β-hydroxyparthenolide. The five-membered ring adopts a twist conformation, whereas the ten-membered ring displays an approximate chair–chair conformation. In the crystal structure, molecules are linked into chains propagating along the b axis by intermolecular O—H...O hydrogen bonds.
Acta Crystallographica Section E. 01/2010;
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ABSTRACT: The title compound, C16H22Cl2O, was synthesized from β-himachalene, which was isolated from essential oil of the Atlas cedar (cedrus atlantica). The asymmetric unit contains two independent molecules, in each of which the six-membered ring shows a half-chair conformation, whereas the seven-membered ring displays a boat conformation. The dihedral angle between the two rings is slightly different in the two molecules [63.22 (13) and 61.81 (14)°].
Acta Crystallographica Section E. 01/2010;
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ABSTRACT: The title compound, C19H32O4, was synthesized from γ-himachalene, wich was isolated from essential oils of Cedrus atlantica. The molecule is built up from two fused six- and seven-membered rings. The six-membered ring has a screw-boat conformation, whereas the seven-membered ring displays a half-chair conformation; the dihedral angle between the mean planes of the rings is 61.99 (6)°.
Acta Crystallographica Section E. 01/2010;
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ABSTRACT: The title compound, C17H22O6, was semi-synthesized from 9-hydroxyarthenolide, which was isolated from the chloroform extract of the aerial parts of Anvillea radiata. The molecule contains fused five- and ten-membered rings: the five-membered lactone ring has a twisted conformation, whereas the ten-membered ring displays an approximate chair–chair conformation. The dihedral angle between the rings is 24.76 (9)°.
Acta Crystallographica Section E. 01/2010;
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ABSTRACT: The title compound, C18H20O3, a hemisynthetic product, was obtained by the reaction of benzoyl chloride and p-methoxythymol. The structure comprises two benzene rings bridged by a carboxyl group; the dihedral angle between the rings is 73.54 (8)°.
Acta Crystallographica Section E. 01/2010;
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ABSTRACT: The title compound, C16H24Cl2O, was synthesized from β-himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H-benzocycloheptene), which was isolated from the essential oil of the Atlas cedar (cedrus atlantica). The molecule forms an extended sheet of two fused rings which exhibit different conformations. The six-membered ring has a half-chair conformation, while the seven-membered ring displays a chair conformation; the dihedral angle between the two rings is 38.2 (1)°.
Acta Crystallographica Section E. 01/2010;
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ABSTRACT: The title compound, C16H22Cl2, a derivative of β-himachalene, was semi-synthesized from natural essential oils of Cedrus atlantica. The molecule is built up from two fused six- and seven-membered rings. The six-membered ring has a perfect chair conformation, whereas the seven-membered ring displays a screw boat conformation; the dihedral angle between the rings is 46.48 (9)°.
Acta Crystallographica Section E. 01/2010;
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ABSTRACT: The title heterocyclic compound, C17H23N3O2S, was synthesized from 4-(4-methylcyclohex-3-enyl)pent-3-en-2-one, which was isolated from Cedrus atlantica essential oil. The thiadiazole ring adopts a flattened envelope conformation, with the flap sp3-hybridized C atom lying 0.259 (1) Å out of the plane of the other four atoms. The screw-related molecules are linked into chains along the b axis by intermolecular N—H...O hydrogen bonds.
Acta Crystallographica Section E. 01/2009;
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ABSTRACT: The racemic title compound, a new terpenoid, C20H29N3O2S·0.5C4H8O2, was synthesized from Cedrus Atlantica essential oil. The compound crystallizes with a disordered ethyl acetate solvent molecule. The thiadiazole ring is almost planar, with a maximum deviation from the mean plane of 0.015 (2) Å for the C atom connected to the isobutyl group and has a puckering amplitude of 0.026 (2) Å. The dihedral angle between the benzene and thiadiazole rings is 18.32 (8)°. The crystal packing involves intermolecular N—H...O hydrogen bonds.
Acta Crystallographica Section E. 01/2009;
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ABSTRACT: The title heterocyclic compound, C20H27N3O2S, was synthesized from 2-(4-methylcyclohex-3-enyl)-6-methylhepta-2,5-dien-4-one, which was isolated from the essential oil Cedrus atlantica. The thiadiazole ring is essentially planar [maximum deviation 0.006 (2) Å] and it forms a dihedral angle of 18.08 (9)° with the benzene ring. The dihedral angle between the thiadiazole ring and the acetamide plane is 7.62 (10)°. In the crystal, molecules are linked into chains running along the c axis by intermolecular N—H...O hydrogen bonds.
Acta Crystallographica Section E. 01/2009;
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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.
Acta Crystallographica Section E. 01/2008;
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ABSTRACT: The new title thiadiazole compound, C14H21N3O2S, was semi-synthesized starting from 1-(4-methylcyclohex-3-enyl)ethanone, a natural product isolated from Cedrus atlantica essential oil. The stereochemistry has been confirmed by single-crystal X-ray diffraction. The thiadiazoline ring is roughly planar, although it may be regarded as having a half-chair conformation. The cyclohexenyl ring has a half-chair conformation. The most interesting feature is the formation of a pseudo-ring formed by four molecules associated through N—H...O hydrogen bonds around a fourfold inversion axis, forming an R44(28) motif.
Acta Crystallographica Section E. 01/2008;
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ABSTRACT: The title compound, C20H28O2, commonly named Sugiol, is a natural oxygenated diterpene that we have isolated for the first time from a hexane extract of the fruits of Juniperus Oxycedrus L. Its X-ray crystal structure determination confirms an abietane skeleton which was predicted by spectroscopic analysis, mainly by 1H and 13C NMR. The cyclohexane ring adopts a flattened chair conformation, while the cyclohexene ring adopts an envelope conformation. The molecules are linked through O—H...O hydrogen bonds to form a zigzag chain extending parallel to the c axis.
Acta Crystallographica Section E. 01/2008;
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ABSTRACT: In the search for cancer chemopreventive agents, we have studied the Diels–Alder reaction of trans-communic acid with tetracyanoethylene in the presence of SiO2 as catalyst. The title cycloadduct, C26H30N4O2, was obtained in 75% yield. The molecules are arranged in pairs through O—H...O hydrogen bonds, forming an R22(8) ring motif. Both the fused cyclohexyl rings adopt a chair conformation, whereas the nonfused ring adopts a half-chair conformation.
Acta Crystallographica Section E. 01/2008;
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Molbank. 01/2006;
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Molbank. 01/2006;
