نتایج جستجو برای: membered rings

تعداد نتایج: 52672  

2009
Bakhodir Tashkhodjaev Mukhlis N. Sultankhodjaev

The title compound, C(34)H(47)NO(12), is the norditerpenoid alkaloid aconifine isolated from the leaves and tubers of Aconitum karakolicum Rapaics. It has a lycoctonine carbon skeleton and contains four six-membered rings and two five-membered rings; its geometry is similar to that observed in other lycoctonine-type diterpenoid alkaloids. There are two intra-molecular O-H⋯O hydrogen bonds which...

2011
Younes Ouzidan Youssef Kandri Rodi Frank R. Fronczek Ramaiyer Venkatraman Lahcen El Ammari El Mokhtar Essassi

The mol-ecular structure of the title compound, C(17)H(20)N(4)O(5), contains a central fused-ring system, comprised of six- and five-membered rings. This unit is linked by C(2) chains to two 2-oxo-1,3-oxazolidine five-membered rings. The central fused-ring system is essentially planar, with a maximum deviation of 0.008 (1) Å from the mean plane. Both oxazolidine five-membered rings are also nea...

2013
Lu Jin Rong-Rong Zhang Hai-Yan Tian Paul Pui-Hay But Ren-Wang Jiang

The title compound, C22H29NO4, a stemona alkaloid, is composed of two lactone rings (A and E), a six-membered ring (B), a pyrrole ring (C) and a seven-membered ring (D). The five-membered rings A and E exhibit envelope conformations (C atoms as flaps) while ring C is planar. Ring B exhibits a twist-chair conformation due to fusion with pyrrole ring C while ring D adopts a chair conformation. Th...

2010
Ahmed Benharref Jean Claude Daran Moha Berraho

The title compound, C(19)H(32)O(4), was synthesized from γ-himachalene, wich was isolated from essential oils of Cedrus atlantica. The mol-ecule 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)°.

2011
Mohamed Moumou Ahmed Benharref Moha Berraho Jean-Claude Daran Mohamed Akssira Ahmed Elhakmaoui

The title compound, C(15)H(18)O(3), was synthesized from 9α-hy-droxy-parthenolide (9α-hy-droxy-4,8-dimethyl-12-methyl-ene-3,14-dioxatricyclo-[9.3.0.0(2,4)]tetra-dec-7-en-13-one), which was isolated from the chloro-form extract of the aerial parts of Anvillea radiata. The five-membered lactone ring has a twisted conformation, while the six- and five-membered rings display chair and envelope conf...

2010
Iván Brito Jorge Bórquez Luis Alberto Loyola Michael Bolte Joselyn Albanez

The title compound (also know as azorellanone), C(20)H(32)O(2), is built up from three fused carbocycles, one five-membered ring and two six-membered rings. The five membered-ring has an envelope conformation, whereas the six-membered rings have a distorted half-chair and a twist-boat conformation. In the crystal, mol-ecules are linked by O-H⋯O inter-actions into zigzag chains with graph-set no...

2008
Hao Shi Hong Xiang Sun

The title compound, C(24)H(32)O(8)S·C(3)H(6)O, features three six-membered and two five-membered rings. The six-membered rings adopt chair, boat and slightly distorted boat conformations whereas one five-membered ring adopts an approximate envelope conformation and the other a twist conformation. Disorder was modelled for the ethyl-thio group with the ethyl-C atoms resolved over three positions...

2013
Ahmed Benharref Jamal El karroumi Lahcen El Ammari Mohamed Saadi Moha Berraho

The title compound, C17H26Br2, was synthesized from β-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzo-cyclo-heptene), which was isolated from the essential oil of the Atlas cedar (Cedrus Atlantica). The asymmetric unit contains two independent mol-ecules with similar conformations. Each mol-ecule is built up from fused six- and seven-membered rings and two appended three-memb...

2012
Bi-Zeng Mao Chao Huang Yu-Zhe Chen Zhen-Er Lv Shao-Yuan Chen

The asymmetric unit in the crystal of the title compound, C(15)H(22)O(3), contains two independent mol-ecules with similar structures. Each mol-ecule contains two six-membered rings and one five-membered ring. The five-membered ring displays an envelope conformation with the C atom linking the epoxy group as the flap, while the two six-membered rings show half-chair conformations. The two indep...

2011
Xiao Lu Gu-Ping Tang Jian-Ming Gu Xiu-Rong Hu

IN THE CRYSTAL STRUCTURE OF THE TITLE COMPOUND [SYSTEMATIC NAME: 2-(4b-fluoro-5-hy-droxy-4a,6a,8,8-tetra-methyl-2-oxo-2,4a,4b,5,6,6a,9a,10,10a,10b,11,12-dodeca-hydro-7,9-dioxa-penta-leno[2,1-a]phenanthren-6b-yl)-2-oxoethyl acetate], C(26)H(33)FO(7), the mol-ecules are connected by inter-molecular O-H⋯O hydrogen bonds into an infinite supra-molecular chain along the b axis. The mol-ecular framew...

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