Methyl 2-(8a-hy­droxy-4a-methyl-8-methyl­enedeca­hydro­naphthalen-2-yl)acrylate

The title compound, C₁₆H₂₄O₃, was synthesized from ilicic acid which was isolated from the aerial part of Inula Viscosa­ (L) Aiton [or Dittrichia Viscosa­ (L) Greuter]. The mol­ecule contains two fused six-membered rings both in chair conformations. In the crystal, mol­ecules are linked into chains running parallel to the a axis by O—H...O hydrogen bonds.

10α-Hy­droxy-4,9-dimethyl-13-(morph­o­lin-4-ylmeth­yl)-3,8,15-trioxatetra­cyclo­[10.3.0.0^2,4.0^7,9]penta­decan-14-one

The title compound, C₁₉H₂₉NO₆, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methyl­ene-3,14-dioxatricyclo­[9.3.0.0^2,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule contains a fused five- and ten-membered ring system. The ten-membered ring adopts an approximate chair–chair conformation, while the five-membered ring is in an envelope conformation, with the C atom closest to the hy­droxy group forming the flap. In the crystal, weak C—H...O hydrogen bonds connect the mol­ecules into layers parallel to (001). An intra­molecular O—H...N hydrogen bond is also present.

9β-Hy­droxy-6,9-dimethyl-3-methyl­ene-3a,4,8,9,9a,9b-hexa­hydro­azuleno[4,5-b]furan-2(3H)-one

The title compound, C₁₅H₁₈O₃, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methylen-3,14-dioxa-tricyclo­[9.3.0.0^2,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The seven-membered ring of the title compound shows a chair conformation, while the five-membered rings exibit different conformations, viz a twisted one for the lactone ring and an envelope conformation for the other five-membered ring with the C atom closest to the hydroxy group forming the flap. In the crystal, O—H...O hydrogen bonds connect mol­ecules into dimers that are inter­connected by C—H...O inter­actions, producing supramolecular chains along the b axis.

Methyl 2-(1a,4a-dimethyl-2,8-dioxo-2,3,4,4a,5,6,7,8-octa­hydro-1aH-1-oxacyclo­propa[d]naphthalen-7-yl)acrylate

The title compound, C₁₆H₂₀O₅, was synthesized from ilicic acid [2-(8-hy­droxy-4a,8-dimethyl­deca­hydro­naphthalen-2-yl)acrylic acid], which was isolated from the chloro­form extract of the aerial part of Inula viscose (L) Aiton [or Dittrichia viscosa­ (L) Greuter]. The molecule is built up from two fused six-membered rings, the epoxidized six-membered ring adopts a half-chair conformation while the other ring displays a perfect chair conformation. The crystal structure features C—H...O hydrogen bonds.

9α-Hy­droxy-12-{[4-(4-meth­oxy­phen­yl)piperazin-1-yl]meth­yl}-4,8-dimethyl-3,14-dioxatricyclo­[9.3.0.0^2,4]tetra­dec-7-en-13-one

The title compound, C₂₆H₃₆N₂O₅, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methyl­ene-3,14-dioxatricyclo­[9.3.0.0^2,4]tetra­dec-7-en-13-one), wich was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule is built up from fused five- and ten-membered rings with the meth­oxy­phenyl­piperazine group as a substituent. The ten-membered ring adopts an approximate chair–chair conformation, while the piperazine ring displays a chair conformation and the five-membered ring a flattened envelope conformation; the C(H)—C—C(H) atoms representing the flap lie out of the mean plane through the remaining four atoms by 0.343 (3) Å. The dihedral angle between the mean planes of the ten-membered ring and the lactone ring is 18.12 (14)°. An intra­molecular O—H...N hydrogen bond occurs. The crystal structure features weak C—H...O inter­actions.

10α-Hy­droxy-13-{[4-(4-meth­oxy­phen­yl)piperazin-1-yl]meth­yl}-4,9-dimethyl-3,8,15-trioxatetra­cyclo­[10.3.0.0^2,4.0^7,9]penta­decan-14-one

The title compound, C₂₆H₃₆N₂O₆, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methylen-3,14-dioxa-tricyclo­[9.3.0.0^2,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule is built up from fused five- and ten-membered rings with two additional ep­oxy ring systems and a meth­oxy­phenyl­piperazine group as a substituent. The ten-membered ring adopts an approximate chair–chair conformation, while the piperazine ring displays a chair conformation and the five-membered ring shows an envelope conformation with the C atom closest to the hy­droxy group forming the flap. The mol­ecular conformation is determined by an O—H...N hydrogen bond between the hy­droxy group and a piperazine N atom. The crystal structure is built up by weak C—H...O inter­actions.

12-{[4-(2-Fluoro­phen­yl)piperazin-1-yl]­meth­yl}-9α-hy­droxy-4,8-dimethyl-3,14-dioxatricyclo­[9.3.0.0^2,4]tetra­dec-7-en-13-one

The title compound, C₂₅H₃₃FN₂O₄, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methyl­ene-3,14-dioxatricyclo­[9.3.0.0^2,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The asymmetric unit contains two independent mol­ecules. In each mol­ecule, the ten-membered ring displays an approximative chair–chair conformation. Each of the piperazine rings adopts a perfect chair conformation, while both lactone rings show an envelope conformation, one with the C atom bearing the piperazin-1-ylmethyl group as the flap, the other with the junction C atom not attached to the ring O atom as the flap. The dihedral angles between the least-squares planes through the ten- and five-membered rings in the two mol­ecules are similar [19.1 (3) and 16.2 (3)°]. An intra­molecular O—H...N hydrogen bond stabilizes the mol­ecular conformation. The crystal packing is stabilized by C—H...O hydrogen bonds.

(1S,2R,3R,6R,7S,8R,10S,11S)-13-{[4-(4-Chloro­phen­yl)piperazin-1-yl]meth­yl}-10-hy­droxy-4,9-dimethyl-3,8,15-trioxatetra­cyclo­[10.3.0.0^2,4.0^7,9]penta­decan-14-one

The title compound, C₂₅H₃₃ClN₂O₅, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methyl­ene-3,14-dioxatricyclo­[9.3.0.0^2,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule is built up from fused five- and ten-membered rings with two additional ep­oxy ring systems and a chloro­phenyl­piperazine group as a substituent. The ten-membered ring adopts an approximate chair–chair conformation, while the piperazine ring displays a chair conformation and the five-membered ring shows an envelope conformation with the C atom closest to the hy­droxy group forming the flap. The mol­ecular conformation is stabilized by an intra­molecular O—H...N hydrogen bond between the hy­droxy group and a piperazine N atom. The crystal structure is stabilized by weak C—H...O inter­actions.

10α-Hy­droxy-13-{[4-(2-hy­droxy­phen­yl)piperazin-1-yl]meth­yl}-4,9-dimethyl-3,8,15-trioxatetra­cyclo­[10.3.0.0^2,4.0^7,9]penta­decan-14-one

The title compound, C₂₅H₃₄N₂O₆, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methyl­ene-3,14-dioxatricyclo­[9.3.0.0^2,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The ten-membered ring adopts an approximate chair–chair conformation, while the piperazine ring displays a near regular chair conformation and the five-membered ring an envelope conformation with the C atom closest to the hy­droxy group forming the flap. The mol­ecular conformation is stabilized by an O—H...N hydrogen bond, which generates an S(7) loop, and the crystal structure features weak C—H...O inter­actions.

1-Isopropyl-4,7-dimethyl-2,8-dinitro­naphthalene

The title compound, C₁₅H₁₆N₂O₄, was synthesized from a mixture of α-himachalene (2-methyl­ene-6,6,9-trimethyl­bicyclo­[5.4.O^1,7]undec-8-ene) and β-himachalene (2,6,6,9-tetra­methyl­bicyclo­[5.4.0^1,7]undeca-1,8-diene) which were isolated from an oil of the Atlas cedar (Cedrus atlantica). The asymmetric unit contains two independent mol­ecules. In each of the two mol­ecules, two O atoms of one nitro group are disordered over two sets of sites with site-occupancy factors of 0.636 (5):0.364 (5) and 0.832 (5):0.168 (5). The crystal structure features weak C—H...O hydrogen bonds.

Methyl 2-(4a,8-Dimethyl-7-oxodeca­hydro­naphthalen-2-yl)acrylate

The title compound, C₁₆H₂₄O₃, was isolated from the aerial part of Inula Viscosa­ (L) Aiton [or Dittrichia Viscosa­ (L) Greuter]. The mol­ecule contains two fused (trans) six-membered rings which both exibit a chair conformation. In the crystal, mol­ecules are linked into chains along [100] by weak C—H...O hydrogen bonds involving the methyl and carbonyl groups.

(1S,3R,8R)-2,2-Dibromo-3,7,7,10-tetra­methyl­tricyclo­[6.4.0.0^1,3]dodec-9-ene

The title compound, C₁₆H₂₄Br₂, 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 is built up from two fused six- and seven-membered rings and an additional three-membered ring from the reaction of β-himachalene with dibromo­carbene. The six-membered ring shows a screw-boat conformation, whereas the seven-membered ring displays a boat conformation; the dihedral angle between the mean planes through the rings is 57.9 (4)°. The absolute structure was established unambiguously from anomalous dispersion effects.

(1S,3R,8R)-2,2-Dibromo-3,7,7,10-tetra­methyltricyclo­[6.4.0.0^1,3]dodec-9-en-11-one

The title compound, C₁₆H₂₂Br₂O, 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 is built up from fused six- and seven-membered rings and an additional three-membered ring from the reaction of himachalene with dibromo­carbene. The six-membered ring has an envelope conformation, with the C atom belonging to the three-membered ring forming the flap, whereas the seven-membered ring displays a screw-boat conformation; the dihedral angle between the rings (all atoms) is 60.92 (16)°.

(1S,3R,8R)-2,2-Dibromo-10-bromo­methyl-3,7,7-trimethyl­tricyclo­[6.4.0.0^1,3]dodec-9-ene

The title compound, C₁₆H₂₃Br₃, 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 is built up from fused six- and seven-membered rings and an additional three-membered ring from the reaction of himachalene with dibromo­carbene. The six-membered ring has an envelope conformation (the flap atom being the C atom shared with the three-membered ring, whereas the seven-membered ring displays a screw boat conformation; the dihedral angle between the rings (defined by the near coplanar atoms) is 56.5 (2)°.