Structure of the product of the reaction of 3,6-dioxa-1,8-(di-2,3-dichloromaleimido)octane with 3,6-dioxaoctane-1,8-diamine

The reaction of 3,6-dioxa-1,8-(di-2,3-dichloromaleimido)octane with 3,6-dioxaoctane-1,8-diamine gave 7,11-diaza-1,4-dioxa-9-en-7,11-oxo-9-chlorobicyclo-[1.2.9]tridecan-8-one. The steric structure of the last was determined by x-ray structural investigation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 394–398, March, 1992.     

Synthesis and olfactory evaluation of the enantiomerically enriched forms of 7,11-epoxymegastigma-5(6)-en-9-one and 7,11-epoxymegastigma-5(6)-en-9-ols isomers,identified in Passiflora edulis

A study on the synthesis of the isomers of the natural C-13 norterpenoids derivatives 7,11-epoxymegastigma-5(6)-en-9-one and 7,11-epoxymegastigma-5(6)-en-9-ols is reported. The latter compounds were prepared from readily available racemic α-ionone and then resolved by mean of lipase-mediated acetylation. The obtained enantiomerically forms were evaluated for their odour properties.     

7,11-epi-thyrsiferol: completion of its synthesis, evaluation of its antimitotic properties, and the further development of an SAR model

We (a) describe the completion of a total synthesis of 7,11-epi-thyrsiferol (4), (b) compare the antimitotic activities of thyrsiferol (2), Delta15,28-dehydrothyrsiferol (3), and 7,11-epi-thyrsiferol (4), (c) evaluate the synergistic behavior of the title compound and colchicine to inhibit cell proliferation, and (d) describe the results of conformational searches that provide additional insight concerning the SAR profile of the thyrsiferol family of natural products.     

RuCl3-TBHP mediated allylic oxidation of Δ lanosterol derivatives

A variety of Δ⁸⁽⁹⁾-lanosterol derivatives were converted into 7,11-dienones using t-butyl hydroperoxide in the presence of ruthenium chloride (RuCl₃) in good yields.     

Four New Lanostane Triterpenoids from Euphorbia humifusa

Four new lanostane triterpenoids, namely (3β)‐3‐hydroxy‐24‐methylenelanost‐8‐ene‐7,11‐dione ( 1 ), (3β)‐3‐hydroxylanosta‐8,24‐diene‐7,11‐dione ( 2 ), (3β,7α)‐3,7‐dihydroxylanosta‐8,24‐dien‐11‐one ( 3 ), and (3β,11β)‐3,11‐dihydroxylanosta‐8,24‐dien‐7‐one ( 4 ) were isolated from Euphorbia humifusa, together with 2 known compounds. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analysis and comparison with the related known compounds.     

Sodium Acetate Catalyzed Multicomponent Cyclization of Aromatic Aldehydes, Acetone and Meldrum Acid

The sodium acetate catalyzed three‐component reaction of aromatic aldehyde, acetone and Meldrum acid or spirolactone at room temperature gave stereospecific 7,11‐cis‐diaryl‐2,4‐dioxaspiro[5,5]undecane‐1,5,9‐triones in a very efficient manner.     

Isolation of a novel triacetoxysecotrinervitane from the termite Constrictotermes cyphergaster (termitidae,sub-family Nasutitermitinae)

A novel secotrinervitane, 3α,9β,15α,-triacetoxy-7,16-secotrinervita-7,11-diene has been isolated from the termite Constrictotermes cyphergaster and its structure assigned by X-ray crystallographic studies on the corresponding trio].     

Stereoselective synthesis of the pink bollworm sex pheromone, (Z,Z)-7,11-hexadecadienyl acetate and its (Z,E)-isomer

Two components of the sex pheromone of the pink bollworm moth, (Z, Z)-7,11-hexadecadienyl acetate and its (Z, E)-isomer, were synthesized employing the Grignard coupling reaction as a key step.     

Two new triterpenes from the seeds of Trichosanthes cucumeroides

Two new triterpenes named 7-oxodihydrokarounitriol (1) and 7,11-dioxodihydrokarounidiol (2), and one known triterpene, 7-oxodihydrokarounidiol (3), were isolated from the unsaponifiable matter of the seeds of Trichosanthes cucumeroides. The structures of 1 and 2 were elucidated as (3alpha, 11beta, 13alpha, 14beta, 20alpha)-3,11,29-trihydroxy-13-methyl-26-norolean-8-ene-7-one, and (3alpha,13alpha,14beta,20alpha)-3,29-dihydroxy-13-methyl-26-norolean-8-ene-7,11-dione on the basis of extensive NMR (1H, 13C, 1H-1H COSY, DEPT, HMQC, HMBC and NOESY) and MS studies.     

Beckmann rearrangement of (+)-3-methoxy-17-methylmorphinan-10-one oxime

(+)6,7,7a,8,9,10,11,11a-Octahydro-2-methoxy-12-methyl-5H-7,11a-irninoethanodibenz[c, e]azepin-5-one ( 3 ) was prepared by Beckmann rearrangement of the oxime of (+)-3-methoxy-17-methylmorphinan-10-one ( 2 ) with polyphosphoric acid.     

Secotrinervitane,a novel bicyclic diterpene skeleton from a termite soldier

The structure of 3α-acetoxy-15β-hydroxy-7,16-secotrinervita-7,11-diene, a diterpene possessing a novel bicyclic cembrane-derived carbon skeleton, has been determined by X-ray diffraction analysis.     

2-Amidinylindole-3-carbaldehydes: synthesis of new tetracyclic compounds containing the pyrrolo[1,2-c]1,4-diazepine ring

2-Amidinylindol-3-carbaldehydes bearing an α-alkoxycarbonyl substituent on the cyclic-tertiary amine moiety were prepared. Pyrolysis of these amidines in diethylenglycol-monoethyl ether produced mainly a pyrrolo[1′,2′-1,2]-1,4-diazepino[5,6-b]indol-7,11-dione. A similar result was obtained starting from 2-amidinylbenzofuran-3-carbaldehyde.     

Insect chemistry—VI: Trifluoromethyl analogs of juvenile hormones

Preparation of two trifluoromethyl analogs of JH-III, methyl 10,11-epoxy-7,11-dimethyl-3-trifluoromethyldodeca-2, 6-dienoate (1a) and methyl 10,11-epoxy-3,11-dimethyl-7-trifluoromethyldodeca-2,6-dienoate (1b) is described. The stereochemistry of trisubstituted double bonds, bearing one trifluoromethyl substituent, could be assigned easily by ¹⁹F NMR spectroscopy. Some peculiarities of the Wittig reactions of trifluoromethyl ketones are indicated.     

席夫碱大环铜配合物的化学核酸酶活性研究

对3种结构相近的席夫碱四氮大环草酰胺铜配合物（CuL^1～3）的化学核酸酶活性进行比较研究。结果表明：这类配合物的化学核酸酶活性与中心金属离子的类型、配体的结构、溶液的pH值、离子强度及配合物的浓度等都有关系。3种配合物表现出来的化学核酸酶活性顺序为CuL³＞CuL²＞CuL¹。CuL³的DNA切割反应表现为典型的假一级连续反应。在80 μmol·L^-1 CuL³和2 mmol·L^-1 H₂O₂的存在下,就超螺旋DNA向切口开环型DNA进而向线型DNA的转化而言,反应速率常数分别为0.044 0±0.001 5 min^-1(k₁)和0.003 52±0.000 18 min^-1(k₂)。     

Insect pheromones and their analogues XXIV. Synthesis of long-chain 1,5-dimethyl-branched pheromones from geranyl acetate

Schemes for the synthesis of long-chain 1,5-dimethyl-branched pheromones (7,11-dimethyloctadecane, 15,19-dimethyltritriacontane, and 2-acetoxy-3,7-dimethylpentadecane) from the product of the allyl oxidation of geranyl acetate (8-acetoxy-2,6-dimethylocta-2E,6E-dien-1-ol) have been developed.     

Uncinatone,a New Antifungal Hydroquinone Diterpenoid from Clerodendrum uncinatum SCHINZ

A new hydroquinone diterpenoid was isolated from Clerodendrum uncinatum SCHINZ (Verbenaceae) by flash chromatography on silica gel. The structure was established as 7,11-dihydroxy-3,4,9,11b-tetramethyl-1,2,8,9,11b-pentahydrophenanthro[3,2-b]furan-6(2H)-one by spectroscopic methods and X-ray analysis. The diterpene was strongly fungitoxic to spores of Cladosporium cucumerinum.     

Preparative separation of bioactive compounds from essential oil of Flaveria bidentis (L.) Kuntze using steam distillation extraction and one step high‐speed counter‐current chromatography

In order to utilize and control the invasive weed, bioactive compounds from essential oil of Flaveria bidentis (L.) Kuntze were studied. Steam distillation extraction and one step high‐speed counter‐current chromatography were applied to separate and purify the caryophyllene oxide, 7,11‐dimethyl‐3‐methylene‐1,6,10‐dodecatriene, and caryophyllene from essential oil of Flaveria bidentis (L.) Kuntze. The two‐phase solvent system containing n‐hexane/acetonitrile/ethanol (5:4:3, v/v/v) was selected for the one step separation mode according to the partition coefficient values (K) of the target compounds and the separation factor (α). The purity of each isolated fraction after a single high‐speed counter‐current chromatography run was determined by high performance liquid chromatography. A 3.2 mg of caryophyllene oxide at a purity of 92.6%, 10.4 mg of 7,11‐dimethyl‐3‐methylene‐1,6,10‐dodecatriene at a purity of 99.1% and 5.7 mg of caryophyllene at a purity of 98.8% were obtained from 200 mg essential oil of Flaveria bidentis (L.) Kuntze. The chemical structures of these components were identified by GC‐MS, ¹H‐NMR, and ¹³C‐NMR.     

Radical mediated stereoselective synthesis of meso-7,11-dimethylheptadecane, a female sex pheromone component of the spring hemlock looper and the pitch pine looper

meso-7,11-Dimethylheptadecane, a female sex pheromone component of the spring hemlock looper and the pitch pine looper, was synthesized from ethyl 2-(bromomethyl)propenoate in nine steps and 14% overall yield. The key step in the synthesis is the highly diastereoselective chelation-controlled radical reaction of diethyl 4-benzyloxy-2,6-dimethyleneheptanedioate with pentyl iodide performed in the presence of 6 equiv of MgBr₂·OEt₂.     

Reaction of unsymmetrical α,β-unsaturated ketones with thiobarbituric acid

Carbocyclization of unsymmetrical 1,5-diarylpenta-1,4-dien-3-ones with thiobarbituric acid afforded previously unknown 7,11-diaryl-3-thioxo-2,4-diazaspiro[5.5]undecane-1,5,9-triones with high regio- and stereoselectivity. The same spiro compounds were also synthesized by three-component condensation of thiobarbituric acid with the corresponding aromatic aldehydes and 4-arylbut-3-en-2-ones.     

Insect pheromones and their analogues XXIV. Synthesis of long-chain 1,5-dimethyl-branched pheromones from geranyl acetate

Schemes for the synthesis of long-chain 1,5-dimethyl-branched pheromones (7,11-dimethyloctadecane, 15,19-dimethyltritriacontane, and 2-acetoxy-3,7-dimethylpentadecane) from the product of the allyl oxidation of geranyl acetate (8-acetoxy-2,6-dimethylocta-2E,6E-dien-1-ol) have been developed.Institute of Chemistry, Bashkir Scientific Center, Urals Branch, Academy of Sciences of the USSR, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 818–823, November–December, 1990.