Insect pheromones and their analogues. XXII. Methyl-branched pheromones based on 4-methyltetrahydropyran. Synthesis of racemic 2-acetoxy-3,7-dimethylpentadecane (diprionyl acetate)

A synthesis is proposed of racemic 2-acetoxy-3,7-dimethylpentadecane — the sex attractant (diprionyl acetate) of plane sawflies of the generaDiprion andNeodiprion on the basis of the regioselective transformation of bifunctional products of the cleavage of 4-methyltetrahydropyran.Institute of Chemistry, Bashkir Scientific Center, Urals Branch, USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 573–576, July–August, 1989.     

The lactones ofFerula malacophylla

Summary 1. From the roots ofFerula malacophylla three sesquiterpene lactones have been isolated: talassin A and the two new ones — malaphyll and malaphyllin.2. On the basis of spectral and chemical characteristics, for malaphyll is proposed the structure of 1-oxo-11-seneciocyloxy-6-veratroyloxyguaia-2,8-dien-4,5-olide, and for malaphyllin 11-acetoxy-1-oxo-6-veratroyloxyguaia-2,8-dien-4,5-olide.V. L. Komarov Institute of Botany, Academy of Sciences of the Azerbaidzhan SSR, Baku. All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 445–449, July–August, 1978.     

Flavonoids from tephrosia—XI: The structure of glabratephrin

Physico-chemical techniques and X-ray crystallography established the structure of glabratephrin, a flavone isolated from Tephrosia semiglabra Sond., as (4'-acetoxy-5',5'-dimethyltetrahydrofuran-2'-one)-3'-spiro-9-(8,9-dihydro-2-phenyl-4H-furo[2,3     

Novel method for the synthesis of (trifluoromethyl)oxirane

The reaction of 3,3,3-trifluoropropene with N-bromosuccinimide in acetic acid at 65—70 °C affords 3-acetoxy-2-bromo-1,1,1-trifluoropropane. When treated with an alkali, the latter is readily converted into (trifluoromethyl)oxirane.     

Cembrenolides of a soft coral Lobophytum sp. (coelenterata, octocorallia, alcyonacea)

The known cembrenolide sarcophin and its new acetoxy derivative — 13-acetoxy-7,8-epoxycembra-1(15),3,11-trien-2,16-olide — have been isolated from the soft coralLobophytum sp.. The compounds isolated are inhibitors of the activity of Na⁺K⁺-ATPase and are membranotropic agents. The structures of the compounds have been shown on the basis of the results of NMR spectroscopy.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 762–765, November–December, 1990.     

Reactions of cage metal siloxanes with functionalized organochlorosilanes

The reactions of [(2-acetoxyetoxy)methyl]dimethylchlorosilane and 1-acetoxy-2-(dimethylchlorosilylmethoxy)benzene with the cage phenylcopper and phenylmanganese siloxanes leads to the cleavage of the M—O—Si bond to give metal chlorides and six-unit cyclosiloxanes with an acetoxy group in the organic substituent at the silicon atom. Methanolysis of these acetoxy derivatives does not affect the ring structure and affords the corresponding polyhydric alcohols.     

Pheromones of insects and their analogs. XX. Methyl-branched pheromones based on 4-methyltetrahydropyran.

A synthesis is proposed of 4,8-dimethyldecanal (VIII) — a pheromone of the flour beetlesTribolium confusum andT. castaneum. By heating 71.2 g of 4-methyltetrahydropyran (I), 83.2 g of AcBr and 1.57 g of ZnCl₂ (45°C), then 120°C, 2 h), 1-acetoxy-5-bromo-3-methylpentane (II) was obtained. The hydrolysis of 19.8 g of (II) (MeOH-H₂O, TsOH, 20°C, 15 h) gave 5-bromo-3-methylpentan-1-ol (III). From 18.1 g of (III) and 38.9 ml of 2,3-dihydropyran (Et₂O, TsOH, 20°C, 20 h) was obtained the 2-THPL ester of (III), (IV), which was converted into 3-methyloct-7-en-1-ol (V) by the treatment of the corresponding Grignard reagent with allyl bromide (THF, CuI-bi-2-pyridyl, 2°C, 4 h, Ar). The interaction of 1.42 g of (V) with Et₃Al (hexane, 20°C, Cp₂ZrCl₂, Ar) gave 3,7-dimethylnonan-1-ol (VI), boiling which with 48% HBr in the presence of concentrated H₂SO₄ gave 1-bromo-3,7-dimethylnonane (VII) which was then converted into the desired (VIII) by the reaction of the corresponding Grignard reagent with DMFA (0–2°C, 1 h; 20°C, 2 h; Ar). The characteristics of the compounds — yield (%), n_D (°C): (I), 79, 1.4340 (22); (III) 89, 1.4660 (23); (IV), 82, 1.4739 (23); (V), 85, —; (VI), 90, 1.4483 (20); (VII), 88, 1.4409 (22); (VIII), 88, 1.4589 (22). Details of the IR and PMR spectra of compounds (II)–(VII) are given.Institute of Chemistry, Bashkir Scientific Center, Urals Branch, USSR Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 272–276, March–April, 1989.     

Structure of the products of oxidation of vindoline by the Sarett reagent

The oxidation of vindoline with the Sarett reagent has given five lactams the structures of which have been established on the basis of the results of instrumental methods of analysis (the x-ray structural method, and the PMR, mass, and IR spectroscopy). Two of the vindoline derivatives — 4-acetoxy-7,8-dihydroxy-16-methoxy-3-methoxycarbonyl-3,6-epoxy-7,8,9,19-tetradehydrovincaminoreine 7,9-betaine and 4-acetoxy-16-methoxy-3-methoxycarbonyl-1-methyl-7,8-dioxo-3,6-epoxyaspidospermidine — have been obtained for the first time and are new compounds.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 551–556, July–August, 1988.     

Synthesis of unsaturated derivatives of 2,5-dimethyl-4-phenylpyridine and 3-methyl-2-azafluorene

A substituted butadiene — 1-phenyl-4-(5-methyl-4-phenyl-2-pyridyl)buta-1,3-diene with a trans, trans configuration — was obtained by condensation of 2,5-dimethyl-4-phenylpyridine with cinnamaldehyde. Two 3-methyl-9-cinnamylidene-2-azafluorene isomers are formed as a result of condensation of the same aldehyde with 3-methyl-2-azafluorene. Data from the PMR and IR spectra were used to prove the configuration of the compounds obtained. It was established that the condensation of 3-methyl-2-azafluorene with salicylaldehyde gives 3-methyl-9-(2-hydroxybenzylidene)-2-azafluorene, which has a zwitterionic structure, and 1,2-bis(3-methyl-2-aza-9-fluorenylidene)ethane. Ideas regarding the chemical mechanism of the formation of the latter are presented. The preparation of an unsaturated alcohol — 3-methyl-9-allyl-2-aza-9-fluorenol — is described.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 82–86, January, 1978.     

Methanolysis and hydrolysis of derivatives of methyl 2,5- and 4,5-dihydrofuran-2-carboxylates

Methyl 2,5-dimethoxy-2,5-dihydrofuran-2-carboxylate is formed in the reaction of HCl-CH₃OH with methyl 5-nitro-2-acetoxy-2,5-, 5-nitro-4-acetoxy-4,5-, and 2,5-diacetoxy-2,5-dihydrofuran-2-carboxylates, whereas methyl 2,5-dioxo-3-pentenoate bis(2,4-dinitrophenylhydrazone) and 4-oxo-2-penten-1,5-dioic acid 2,4-dinitrophenylhydrazone are isolated in the presence of 2,4-dinitrophenylhydrazine. Methyl 5-nitrofuran-2-carboxylate is formed by treatment of methyl 5-nitro-2-acetoxy-2,5-dihydrofuran-2-carboxylate with aqueous solutions of acetic or phosphoric acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1600–1603, December, 1977.     

Steroid analogs without the B ring

Conclusions A new scheme of synthesis was devised for 3-ethyl-4-p-methoxypheny1-2-methy1-3-cyclohexene-1-carboxylic acid — an analog of dehydrodoisynolic acid with a deeyclized ring B —in which the key stage is the diene condensation of 3-ethyl-2-p-methoxyphenyl-1,3-pentadiene with acrylic acid.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 624–628, March, 1967.     

Transformed steroids. 186. Use of the diacetoxyiodobenzeneiodine system for the conversion of epimeric 17-ethynylandrost-4-en-17-ol-3-ones to pregnanes

Epimeric 17-acetoxy-17-ethynylandrost-4-en-3-ones react with diacetoxyiodobenzene and iodine in acetic acid or methanol in an unusual manner to give 17-acetoxy-21,21-diiodo-17-pregn-4-en-3,20-diones, which are then converted to 21-monoiodides and 21-acetates. Epimeric 17-hydroxy-17-ethynylandrost-4-en-3-ones are inert under these conditions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2875–2878, December, 1991.     

Effect of the inclusion of a cyclic fragment in the chromophore on the properties of a spiropyran-merocyanine system

The corresponding merocyanines, which do not display a tendency to form spiropyran structures, are formed in the condensation of 1,3,3-trimethyl-2-methyleneindoline with 5-methyl-2-furoylacetaldehyde, 2-formylcyclohexanone, or 2-formyl-1-tetralone. Spiran compounds in which the spiropyran—merocyanine equilibrium is shifted markedly to favor the closed form are formed when 4a,9-dimethyl-2,3,4,4a-tetrahydrocarbazone — the cyclic analog of the Fischer base — is used in the reaction with salicylaldehydes and benzoylacetaldehydes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1205–1210, September, 1982.     

N-3-oxoalkylamides and-thioamides in synthesis of heterocyclic compounds.

Previously unknown 6-acetoxy-5,6-dihydro-4H-1,3-oxazinium perchlorates were obtained by reacting N-3-oxoalkylamides with perchloric acid in acetic anhydride. It was found that the reaction of 6-acetoxy-5,6-dihydro-4H-1,3-oxazinium perchlorates with sodium hydrosulfide yields N-3-oxoalkylthioamides.See [1] for Communication 1.Omsk State University, Omsk 644077. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1688–1692, December, 1997.     

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.     

Rearrangement of 1-acetylindoxyl oxime into 1-acetyl-2-acetoxy-3-iminoindoline hydrosulfate

1-Acetyl-2-acetoxy-3-iminoindoline hydrosulfate was obtained by rearrangement of 1-acetylindoxyl oxime by the action of concentrated H₂SO₄. The hydrolysis and oxidative dimerization reactions of the above iminoindoline hydrosulfate were investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 329–331, March, 1990.     

Three-step synthesis of 4-(2′-hydroxyethyl) azetidin-2-one and its substituted derivatives from 4-acetoxy-2-pyridones

4-(2'-Hydroxyethyl)azetidin-2-one, an important synthetic intermediate for carbapenem, and its substituted derivatives have been synthesized from 4-acetoxy-2-pyridones by photolysis, catalytic hydrogenation, followed by basic hydrolysis in the presence of sodium borohydride.