Synthesis of Schiff bases on the basis of the isosteviol terpenoid

The transformation of the carboxy and keto groups of the isosteviol (ent-16-ketobeyeran-19-oic acid) diterpenoid was used to synthesize its new nitrogen-containing derivatives, including Schiff bases by the C⁴ and C¹⁶ atoms of the isosteviol frame. The structure of the resulting compounds was established by X-ray diffraction.     

Alkylation of aldehyde oxime dianions

In contrast to an earlier report, aldoximes can be deprotonated to their dianions and alkylated in high yield.     

Mechanical activation of the KOH-DMSO superbase system and its use in the reaction with cyclohexanone

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2879–2880, December, 1989.     

O-Alkylation of diterpenoid steviol in the system KOH-DMSO

Steviol reacted with benzyl bromide and 1,9-dibromononane in the system KOH-DMSO to give the corresponding O-alkylation products at the carboxy group. The reaction of steviol with methyl iodide was accompanied by alkylation of the hydroxy group and rearrangement of the carbon skeleton.     

One-electron transfer in the vinylation of 4,5,6,7-tetrahydroindole with acetylenes in the system KOH-DMSO

It has been shown by EPR, using 2-methyl-2-nitrosopropane as a radical trap, that vinylation of 4,5,6,7-tetrahydroindole with phenylacetylene in the system KOH-DMSO involves the formation of the 4,5,6,7-tetrahydroindolyl radical by transfer of an electron from the 4,5,6,7-tetrahydroindole anion to the acetylene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 142–144, January, 1990.     

Formation of vinyloxyethene from 1,2-divinyloxyethane in the KOH-DMSO system

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2873–2874, December, 1989.     

Reaction of cyclic ketones with KOH-DMSO

Upon reaction of cycloalkanones with a KOH-DMSO system 2-methylenecycloal-kanols are formed, the yield (10–37%) of which decreases in the series: cyclohexanone > cycloheptanone > cyclooctanone > cyclododecanone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1601–1605, July, 1990.     

Nucleophilic addition of phosphine to 4-chlorostyrenes in the KOH-DMSO system

In the superbasic system KOH-DMSO (H₂O) at 60–75 °C (2–2.5 h, atmospheric pressure), 4-chlorostyrene and 4-chloro-α-methylstyrene add phosphine at the double bond to form 1: 1 and 2: 1 anti-Markovnikov adducts in 10–18% and 58–67% yields, respectively.     

Cascade assembly of frontalin derivatives from cyclohexanone and acetylene in the system KOH-DMSO

Russian Journal of Organic Chemistry -     

New examples of the vinylation of NH-heterocycles with acetylene at atmospheric pressure in the KOH-DMSO system

Vinylation of 2-hetarylpyrroles, 4,5-dihydrobenzo[g]indole, and 1,2,3,4-tetrahydro--carbinols at atmospheric pressure in the superbasic system KOH-DMSO at 100–120 ° C has given the corresponding N-vinyl derivatives in yields of 92–99%.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 481–485, April, 1986.     

N-alkylation products of substituted imidazoles and dihydropyrimidinediones with dibromoalkanes

The reactions of N-containing heterocycles with dihaloalkanes were studied. All structures were determined by NMR and mass techniques. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 31–34, January, 2007.     

Nitromethane Reaction with Acetylene in KOH-DMSO System

Russian Journal of Organic Chemistry -     

Reaction of Red Phosphorus with Allylbenzene in Superbasic System KOH-DMSO

Abstract

Red phosphorus reacts with allylbenzene in the superbase system KOH-DMSO (130°C, 3 h, Ar) to give a mixture of bis(1-methyl-2-phenylethyl)phosphane (1), bis(1-methyl-2-phenylethyl)phosphane oxide (2), and 1-methyl-2-phenylethylphosphinic acid (3). Secondary phosphane oxide 2 and phosphinic acid 3 have been isolated from this mixture in 35% and 32% yield, respectively. Microwave activation of the reaction (200 W, 30 min) affords secondary phosphane 1 as the main product in 48% yield.

GRAPHICAL ABSTRACT      

Formation of free radicals in the vinylation of 2-substituted pyrroles with acetylenes in a KOH-DMSO system

By spin trapping, using 2-methyl-2-nitrosopropane (t-BuNO), the EPR signals of vinyl-tert-butylnitroxyls and spin adducts of t-BuNO with products of the addition of 2-substituted pyrrole radicals to acetylenes were recorded during the vinylation of 2-substituted pyrroles with acetylenes in a KOH-DMSO system. The 2-substituted pyrrole radicals have a high stability, and their EPR spectra were observed directly in the vinylation reactions. It is shown that one-electron transfer processes are involved in vinylation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1056–1062, August, 1992.     

Behavior of Allylamines in the System KOH-DMSO

Isomerization of triallylamine in the system KOH-DMSO at 90-100°C leads to formation of tris-(1-propenyl)amine in quantitative yield. Under similar conditions, diallyl(ethyl)amine is converted into ethyl-bis(1-propenyl)amine, 1-ethyl-3-methylcyclohexane. Diallylamine in KOH-DMSO gives rise to a complexmixture of products consisting of bis(1-propenyl)amine, methylbis(1-propenyl)amine, 1-ethyl-3-methylcyclo-hexane, and 2-ethyl-3,5-dimethylpiperidine. Ways of formation of these products are discussed.     

Reaction of hexafluoropropylene and its oligomers with acetone oxime

Reactions of perfluoropropylene and its oligomers with acetone oxime in the presence of a base afford perfluoroalkyl and/or perfluoroalkenyl ethers of acetone oxime. When heated to 100 °C, the 3-perfluoro-2-methyl-2-pentenyl ether of acetone oxime (3) is quantitatively converted to 4-hydroxy-3-methyl-5,5-bistrifluoromethyl-4-pentafluoroethyl-1-pyrroline (4), the structure of which was established by X-ray diffraction analysis. A convenient one-stage synthesis of perfluoro-3-isopropyl-4-methyl-3-penten-2-one (7) was proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1068–1072, June, 1994.     

Reaction of isosteviol diterpenoid with selenium dioxide

Diterpenoid isosteviol was oxidized by selenium dioxide in acetic anhydride or in a mixture of acetic anhydride with dioxane to 15-oxo-derivative, whereas reaction with SeO₂ in boiling ethanol led to a mixture of mono- and diselenides. Molecular structure of the monoselenide is established by the X-ray structural analysis.