Insect pheromones and their analogues. XLVI. Synthesis of 13RS-hydrooxytetradec-5Z-enoic acid — The acyclic precursor of the macrolide component of the pheromone of Cryptolestes pusillus

New routes for the synthesis of 13RS-hydroxytetradec-5Z-enoic acid — the acyclic precursor of the macrolide component of the pheromone ofCryptolestes pusillus have been developed on the basis of the readily accessible 1-methylcycloocta-1Z, 5Z-diene or isopropyl nona-3E,8-dienoate.Institute of Biological Plant Protection, Moldovian Academy of Sciences, Kishinev. Scientific-Research Institute of Forestry and Forestry Mechanization, Pushkino. Moscow Institute of Wood Technology; and Georgia Institute of Mountain Forestry, Tbilisi. Translated from Khimiya Prirodnykh Soedeninii, No. 1, pp. 150–155, January–February, 1993.     

Insect pheromones and their analogues XLIII. Chiral pheromones from (S)-(+)-3,7-dimethylocta-1,6-diene 3. Synthesis of (4R)-4-methylnonan-1-OL — Sex pheromone of Tenebrio molitor and its racemic analogue

Starting from the readily available enantiomerically enriched (S)-(+)-3,7-dimethylocta-1,6-diene (ee ≃ 50%), we have synthesized (4R)-4-methylnonan-1-ol — the sex pheromone of the yellow mealworm bettleTenebrio molitor L. A scheme for synthesizing the racemic analogue of the pheromone from 4-methyltetrahydropyran has been developed. Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 711–714, November–December, 1992.     

Orifluoroacetylation and dehydration of 20-hydroxyecdysone acetonides. Synthesis of stachisterone B

Orifluoroacetylation of the 25(OH)-group with subsequent dehydration of the 14(OH)-group takes place in the reaction of 20-hydroxyecdysone 20,22-acetonide and 2,3:20,22-diacetonide with trifluoroacetic anhydride in the presence of pyridine. Dehydration of the 14(OH)-group gives rise to stachisterone B derivatives, which are hydrolyzed to give the phytoecdysteroid stachisterone B.     

Synthesis ofS-(+)-hydroprene

A novel path toS-(+)-hydroprene (1) starting from the technical gradeS-(+)-dihydromyrcene (2, e.e. 50%) is proposed. The latter was selectively transformed intoS-3,7-dimethyloctanal (5) in three steps including hydroalumination. The reactions of5 with allyl- or methallylmagnesium chloride followed, respectively, either by oxygenation in the presence of PdCl₂/CuCl or by ozonolysis, affordS,E-6,10-dimethyl-3-undecen-2-one (7) which was treated with ethoxyethynylmagnesium bromide to give the title juvenile hormone analogue in 23% overall yield.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No 1, pp. 110–112, January, 1993.     

Pheromones of insects and their analogs. XXVII. Synthesis of 10-hydroxy-4,8-dimethyldeca-4E,8E-dienoic acid and of racemic 4,8-dimethyldecanal from geranyl acetate

10-Hvdroxy-4,8-dimethyldeca-4E,8E-dienoic acid and racemic 4,8-dimethyldecanal (components of beetle pheromones) have been synthesized from geranyl acetate.Institute of Chemistry, Bashkir Scientific Center, Urals Branch, Academy of Sciences of the USSR, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 272–276, March–April, 1991.     

Use of enyne compounds in the synthesis of insect pheromones

A new approach has been developed to the synthesis of monogenic insect pheromones with acetogenin and macrolide structures, using the low reactivity of ozone and of 9-borabicyclo[3.3.1]nonane towards an acetylenic function as compared with a vinyl function.Institute of Organic Chemistry, Ufa Scientific Center of the Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, Vol. 33, No. 1, pp. 34–41, January–February, 1997.     

Insect pheromones and their analogs. VIII. Synthesis of the (Z) and (E) isomers of 2-methyloctadec-7-ene and of 2-methyl-7,8-epoxyoctadecane

A highly stereospecific method for the synthesis of racemic (Z)-disparlure has been developed which is based on the reduction of 2-methyloctadec-7-yne with the aid of 9-borabicyclo[3.3.1]nonane and the epoxidation of the resulting (Z)-2-methyloctadec-7-ene with p-methoxycarbonylperbenzoic acid. The¹³C NMR spectra of the (Z) and (E) isomers of 2-methyloctadec-7-ene and 2-methyl-7,8-epoxyoctadecane, which unambiguously confirm the structures of these compounds, are given. It has been established that (E)-2-methyloctadec-7-ene exhibits a moderate attractant activity while the (Z) isomer does not attract the gypsy moth. The addition of 5–25% of (E)-disparlure increases the biological activity of (Z)-disparlure.Institute of Chemistry, Bashkir Branch, Academy of Sciences of the USSR, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 630–634, September–October, 1983.