نتایج جستجو برای: membered rings
تعداد نتایج: 52672 فیلتر نتایج به سال:
In the title compound, C(15)H(16)BrNO(3)S, the boat form of the six-membered ring is almost symmetrical with respect to the ep-oxy bridge. The two five-membered rings generated by the ep-oxy bridge of the six-membered ring adopt envelope conformations, whereas the N-containing five-membered ring adopts a twisted conformation. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds.
Two cyclic alkyl(aryl)boranes, a 1-bora-indane derivative 1, and a tricyclic derivative 4, containing the boron atom in a six-membered ring, were structurally characterized by NMR techniques in solution. The solid-state structure of the 1-bora-indane 1 was determined by X-ray crystallography. The reactivity of these cyclic alkyl(aryl)boranes towards monoalkynyltin compounds, Me3Sn–C≡C–Me and Me...
The title mol-ecule, C16H9BrO3, deviates slightly from planarity. The benzene ring makes a dihedral angle of 1.02 (9)° with the plane defined by the five-membered ring of the indandione moiety. The latter exhibits a minute twist indicated by the dihedral angle of 0.47 (9)° between the planes of the five- and six-membered rings. An intra-molecular C-H⋯O hydrogen bond between the attached benzene...
THE TITLE COMPOUND [SYSTEMATIC NAME: 11β-hydr-oxy-24,25-ep-oxy-3,16-oxo-protost-13 (17)-en-23-yl acetate], C(32)H(48)O(6), a protostane-type triterpenoid, was isolated from the Chinese herbal medicine alismatis rhizoma (the rhizome of Alisma orientalis Juzep). The mol-ecule contains four trans-fused rings, viz. three six-membered and one five-membered ring. Two of the six-membered rings have sl...
The title compound, C(19)H(29)O(4), was synthesized from 9α-hy-droxy-parthenolide (9α-hy-droxy-4,8-dimethyl-12-methylen-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 mol-ecule is built up from two fused five- and ten-membered rings with the pyrrolidin-1-ylmethyl group as a substituent. The fi...
The title compound, C16H24Br2O, was synthesized from the reaction of β-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzo-cyclo-heptene), which was isolated from Atlas cedar (Cedrus atlantica) essential oil, after reaction with di-bromo-carbene. The asymmetric unit contains two independent mol-ecules with similar conformations. Each mol-ecule is built up from fused six-and seven...
The title compound, C(17)H(18)N(2)O(4), is the methyl ester of the adduct of intra-molecular Diels-Alder reaction between maleic anhydride and 1-(2-fur-yl)-2,3,4,5-tetra-hydro-1H-pyrrolo-[1,2-a][1,4]diazepine. The mol-ecule comprises a fused penta-cyclic system containing four five-membered rings (viz. pyrrole, 2-pyrrolidinone, tetra-hydro-furan and dihydro-furan) and one seven-membered ring (1...
The title compound, C(19)H(29)NO(5), was synthesized from 9α-hy-droxy-parthenolide (9α-hy-droxy-4,8-dimethyl-12-methylen-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 mol-ecule is built up from two fused five- and ten-membered rings with the (morpholin-4-yl)methyl group as a substituent. Th...
The title compound, C(20)H(31)NO(5), was synthesized from 9α-hy-droxy-parthenolide (9α-hy-droxy-4,8-dimethyl-12-methylen-3,14-dioxa-tricyclo-[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 mol-ecule is built up from fused five-and ten-membered rings with the pipyridin-1-yl-methyl group as a substituent. The ten...
The title compound, C19H19NO5, (I), is the product of a domino reaction between cotarnine chloride and acetyl-acetylene catalysed by copper(I) iodide. The mol-ecule of (I) comprises a fused tetra-cyclic system containing two terminal five-membered rings (pyrrole and 1,3-dioxole) and two central six-membered rings (di-hydro-pyridine and benzene). The five-membered 1,3-dioxole ring has an envelop...
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