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The Ritter-type reaction of alkyl perchlorates with nitriles of various structures was systematically studied. The reaction has a wide scope and proceeds under extremely mild conditions without any catalysts or special activation of reagents. A structural diversity of the obtained by the Ritter-type reaction N-alkyl amides bearing small ring, double bonds, additional functional groups, aromatic and adamantane fragments, was demonstrated.

Two dispiro[cyclopropane-1,3’-bicyclo[3.3.1]nonane-7′,1″-cyclopropanes] were treated with various oxidative systems. The conditions providing mono- or dioxidation of the CH2 groups neighbouring to spiro-annulated cyclopropane moieties to afford the corresponding mono- or diketones were found.

Novel N-(1-oxidopyrimidin-4-yl)- and N,N′-bis(1-oxidopyrimidin-4-yl)diamines were prepared from 4-fluoropyrimidine N-oxides and diamines basing on SNAr reaction. One compound from this series possessed antiviral activity against tick-borne encephalitis virus (TBEV).

Tetraspiro[2.1.2(5).1.2(9).1.2(13).1(3)]hexadecane-1,3,5,7-tetraone 4, a unique tetraketone containing a cyclooctane core and four spiroannelated cyclopropane moieties, represents the previously unknown cyclotetramer of carbonylcyclopropane. For this purpose oxidation of the parent polyspirocyclic hydrocarbon was examined under various oxidative conditions, and the reactivity of oxidants towards methylene groups of the eight-membered cycle, activated by adjacent spirocyclopropane rings, was evaluated and contrasted. Whereas the treatment of tetraspirohexadecane with ozone resulted in monooxidation, its reaction with methyl(trifluoromethyl)dioxirane afforded the product of four-fold oxidation, triketoalcohol 10. Subsequent oxidation of the latter with Dess-Martin periodinane gave the target tetraketone 4.

Reactions of oxidative nucleophilic substitution of alkyl iodides with lithium perchlorate and dinitramide were studied. The reactions of alkyl iodides and lithium perchlorate, proceeding in the presence of nitronium tetrafluoroborate as an oxidant, furnished a series of new alkyl perchlorates, including those containing an adamantyl fragment. Spectral properties of alkyl perchlorates were studied in detail for the first time. The reactions of oxidative nucleophilic substitution of iodoacetic ester and lithium dinitramide, proceeding upon treatment with nitronium tetrafluoroborate or ozone, resulted in the substitution of an iodine atom with the nitrate anion.

5-Aminoisoxazoles containing trimethoxy- and methylenedioxyphenyl moieties were prepared by heterocyclization of electrophilic alkenes with tetranitromethane in the presence of triethylamine with subsequent reduction of resulting 5-nitroisoxazoles. The crystal structure of 3,4,5-trimethoxybenzyl 5-aminoisoxazole-3-carboxylate was determined by X-ray analysis. Two novel 5-aminoisoxazoles demonstrated moderate antimitotic activity to human lung carcinoma A549 cell line.

Reduction by using SnCl2 of easily accessible 5-nitroisoxazoles substituted with an electron-withdrawing group (EWG) has been studied. Whereas the reaction in ethanol yielded 5-aminoisoxazoles, performing the reaction in tetrahydrofuran gave previously unknown 5-[hydroxy(tetrahydrofuran-2-yl)amino]isoxazoles. Both reduction procedures were optimized to afford the corresponding products in good to excellent yields. Some mechanistic details concerning the inclusion of the tetrahydrofuranyl moiety into the reaction product are discussed

A number of new alkoxy- and phenylsulfanyl-substituted 1,1-dihalospiro[2.2]pentanes bearing different halogen atoms were synthesized. 1,1-Dihalo-4-tert-butoxyspiro[2.2]pentanes reacted with methyllithium at −55 to −10°C to give exclusively 1-tert-butoxy-2-vinylidenecyclopropane. The reaction of 1-bromo-1-fluoro-4-phenylsulfanylspiro[2,2]pentane with methyllithium resulted in replacement of the fluorine atom by methyl group.

A novel approach to nitro-substituted cyclopropanes and spiropentanes via oxidation of the corresponding amines with dimethyldioxirane is reported. The method is used successfully for the preparation of a series of nitrocyclopropanes as well as for the first synthesis of 1,4-dinitrospiro[2.2]pentane.

A skeletal rearrangement of a series of polyspiro internal gem dibromocyclopropanes in the presence of methyllithium reagents was studied. The rearranged products of two types were obtained: substituted bromocyclobutenes (type B) and C-H insertion products (type K) resulting from the reaction of the carbenoid intermediate H with the ether solvent. The mechanism of the carbenoid rearrangement is discussed.

83 The reaction of olefins with polynitromethanes is a known method for the preparation of 3,3-dinitroisoxazolidines [1, 2]. Previously, we studied reactions of tetranitromethane and halotrinitromethanes with unsaturated compounds containing small rings [3–8]. It was shown that the reactions of polynitromethanes with strained alkenes and acetylenes give a range of Nand O-containing heterocycles (dinitroisoxazolidines, nitroisoxazolines, dinitropiperidones, dinitroaziridines), tetranitropropanes, and gem -dinitrocyclopropanes [3–9]. No data on reactions of oxiranes with polynitromethanes have been reported so far, although these reactions can be considered as a new method for generation of alkyl nitronates, which are precursors of diverse heterocycles, and as a possible approach to the synthesis of trinitroalkanols. The trinitromethyl anion is known to show ambident properties, functioning as either an Oor a C-nucleophile depending on the substrate nature [1, 4, 7]. We suggested two possible pathways for its reaction with epoxides (Scheme 1), namely, pathway A including C-alkylation of the oxonium cation I to give 3,3,3-trinitropropanols II (two-component reaction) and pathway B including O-alkylation of the oxonium cation I with generation of an unstable nitronic ester III, which can either decompose to α -hydroxy ketone IV or undergo [3+2]-cycloaddition in the presence of an olefin to give 3,3-dinitroisoxazolidines V (three-component reaction).

The synthesis of cyclopropyl- and cyclobutyl-substituted α-aminophosphonates by three-component microwave-assisted reaction of cyclopropanecarbaldehydes, benzylamine, and diethyl phosphite in the presence of cadmium iodide as catalyst has been developed.

A facile general method has been developed for the synthesis of 5-substituted 3-nitroisoxazolines by the application of a thermal P-elimination reaction to N-alkoxy-3,3-dinitroisoxazolidines in chlorobenzene.

Reactions of tetranitromethane with a number of di- and trisubstituted olefins in nitromethane were studied. Vinylcyclopropanes and phenylcycloalkenes reacted with tetranitromethane in an unexpected fashion, leading to formation of alkyltrinitromethanes and vicinal nitro alcohols.

Previously, V.A. Tartakovskii and coworkers [1] suggested a synthetic methodology based on cycloaddition reactions of 4-hydroxy-3-nitroisoxazoline N -oxide ( I ) to olefins, followed by the cleavage of nascent bicyclic cycloadducts with bases, which can be considered a convenient and versatile procedure for preparing nitroisoxazolines. The use of strained cyclic and polycyclic alkenes as dipolarophiles in this reaction is of particular interest, because it considerably expands the synthetic possibilities and the range of applicability of this method. We studied the reaction of N -oxide ( I ) with the following small-ring olefins ( II – V )

Adducts of bromo- and dibromocarbenes with bicyclo[6.1.0]non-2-ene and tricyclo-[8.1.0.01 , 9.04 , 6]deca-2,6-diene were studied in reaction with potassium tert-butylate in DMSO. The main process was formation of polycyclic cyclopropenes.

Methods have been developed for the synthesis of 3,5-dimethyl-4-(2-N-mono- and -disubstituted and also unsubstituted aminoethyl)pyrazoles from 1,1-diacetylcyclopropane.

Dehydrohalogenation of three isomeric adducts of dichlorocarbene with bicyclo[6.1.0]non-1-,-2-, and-4-enes under the action of potassiumtert-butoxide in DMSO was studied. In the course of dehydrohalogenation of the substrates under study, different isomerization processes, which were accompanied by repeated migrations of multiple bonds that formed, occurred depending on the structure of dichlorides, while no skeletal rearrangements were observed.

Three-component one-pot reactions of tetranitro- and bromotrinitromethanes with alkoxyacetylenes, mediated by diazomethane or bicyclobutylidene, yielding gem -dinitroaziridines via sequential electrophile transfer followed by [3+2]-cycloaddition, have been studied. A series of novel N -alkoxy-2,2-dinitroaziridines have been prepared by these reactions.

The substrates are nitrated regio- and stereoselectively to give nitroalkenes and nitro alcohols.

A convenient method for the preparation of β-tosylamino nitrates based on the ring-opening reaction of aziridines by tetranitromethane in the presence of triethylamine is described. A series of substituted β-amino nitrates is obtained in high yields under mild conditions.

Reactions of tetranitromethane with unsaturated hydrocarbons containing small cycles were studied. Methylenecyclobutanes with tetranitromethane give rise to cyclobutane derivatives of 3,3-dinitroisoxazolidine. The resultsof tetranitromethane addition to cyclopropane olefins are completely determined by the structure of the olefin substrate.

A series of novel gem-bromofluorospiropentanes were synthesized and investigated in the reaction with methyllithium. Either substitution of the fluorine atom for a methyl group or rearrangement into methylated cyclobutene derivatives occurred under these conditions.

A series of new substituted gem-dibromospiropentanes was studied in a reaction with methyllithium at −55...−50°C. This reaction is a carbenoid rearrangement that leads to the formation of monomeric and dimeric bromocyclobutenes and also to the products of cyclobutylidene insertion into a C-H bond of the solvent depending on the character of substituents in the dibromospiropentane fragment.

A convenient regioselective method for the preparation of β-hydroxy nitrates based on the ring opening reaction of epoxides by tetranitromethane in the presence of triethylamine is described. A series of substituted β-hydroxy nitrates were obtained in high yields under mild conditions.

Reaction of 2,2-dibromotricyclo[7.1.01,9.01,3]decane with methyllithium gives strained cyclic allene 1 containing an ethenylidene-cyclopropane unit in a nine-membered ring and dimer 6 resulting from a dibromotriangulane rearrangement.