Laboratory and Industrial Applications of Microwave Techniques

The use of microwave techniques in scientific research is reviewed. Also some semicommercial-scale microwave units are examined.     

Homolytic telomerization of vinyltrimethylsilane with 5,5-dimethyl-1,3-dioxane

The homolytic telomerization of vinyltrimethylsilane by 5,5-dimethyl-1,3-dioxane follows three principal routes, with the formation of 2- and 4-substituted 5,5-dimethyl-1, 3-dioxanes and a formate ester. The rings in the reaction products (2-trimethylsilylethyl- and 4-trimethylsilylethyl-5,5-dimethyl-1,3-dioxane) exist in the chair conformation. The substituants in the 2- and 4-positions of the dioxane ring occupy equatorial positions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1031–1035, August, 1986.     

Dynamics of the accumulation of the alkaloids ofReseda luteola structure of lutine and lutinine

Summary The biosynthesis of the alkaloids ofAmmothamnus lehmannii Bge. have been studied by supplying the plants with [1,5-¹⁴C₂] cadaverine. It has been shown that cadaverine is a precursor of sophocarpidine, sophocarpine, and pachycarpine. Possible routes of interconversions have been studied by supplying the plants with the tritium-labelled alkaloids [³H] sophocarpine, [³H] matrine, and [³H] pachycarpine.V. I. Lenin Tashkent State University. Institute of Plant Biochemistry, Academy of Sciences of the German Democratic Republic, Halle. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 776–780, November–December, 1976.     

Homolytic addition of 1,3-oxathiolane to unsaturated hydrocarbons

The homolytic addition of 1,3-oxathiolane to olefins takes place with the formation of 2-substituted 1,3-oxathiolanes and insignificant amounts of functional derivatives of sulfides.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 259–263, February, 1986.     

Catalytic oxidation of cycloalkane heteroanalogs as a way to polyfunctional compounds

Liquid phase oxidation of cycloalkane diheteroanalogs catalyzed by compounds of Cu²⁺, Ni²⁺, Co²⁺, Cr³⁺, Fe³⁺ has been studied. It has been established that these catalysts can be applied to intensify, oxidize and increase the selectivity of this process.

---

: Cu², Ni²⁺, Co²⁺, Cr³⁺, Fe³⁺. .

     

Synthesis of methyl-branched low-molecularmass insect bioregulators from the products of the acid decyclization of 4-methyltetrahydropyran

This review generalizes work on the chemoselective synthesis of racemic methyl-branched insect pheromones and the juvenoid hydroprene from 1,5-bifunctional 3-methylpentanes produced by the acid opening of the ring of 4-methyltetrahydropyran.Institute of Organic Chemistry, Ufa Scientific Center, Russian Academy of Sciences. Scientific-Research Institute of Fine Organic Synthesis Academy of Sciences of the Republic of Bashkortostan, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 170–177, March–April, 1977.     

Homolytic alkylation of quinaldine and quinoxaline with 18-crown-6

Homolytic alkylation of protonated quinoxaline with 18-crown-6, initiated by the system pivalic acid-iron(II) sulfate at 20–25C, gives (quinoxalin-2-yl)-18-crown-6 in 85% yield. Under analogous conditions, the reaction with quinoline affords two isomers: (quinolin-4-yl)-18-crown-6 and (quinolin-2-yl)-18-crown-6, in yields of 20 and 30% respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 75–76, January, 1988.     

Kinetics and mechanism of the reaction of 1,2-diethoxyethane hydroperoxide with ozone

The kinetics and products of the reaction of 1,2-diethoxyethane hydroperoxide with ozone in CCl₄ solution at 9 and 22°C have been studied. A reaction mechanism is proposed.

---

I,I- CCl₄ (9; 22°C). .

     

Character of intermediate radicals in homolytic isomerization of cyclic acetals and their heteroanalogs

Conclusions Employing the EPR method and 2-methyl-2-nitrosopropane as the spin trap, we recorded the formation of the radicals (n = 1 and 2; X = O, N, or a chain composed of C and O atoms; R = H or alkyl) during the photolysis of acetals and their heteroanalogs in the presence of di-tertbutyl peroxide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2097–2099, September, 1976.The authors are indebted to A. Sh. Mukhtarov for assistance in running the experiments.