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A convenient method for the synthesis of ω- and (ω – 1)-acetylenic acids involves free-radical oxidative scission of cycloalkanones containing five-, six, or seven-membered cycles to give the corresponding ω-olefinic acids followed by bromination of the latter and subsequent dehydrobromination under the action of alkalis.

Reactions of cycloalkanone enamines with H2O2 gave bis(1-morpholinocyclopent-1-yl)- and bis(1-morpholinocyclohex-1-yl)-peroxides, which were studied by NMR spectroscopy and X-ray diffraction. Thermolysis of bis(1-morpholinocyclohex-1-yl)-peroxide in n-hexane resulted in two major products, viz., cyclohexanone and morpholine.

The cocrystallization of di( cis -2-carboxycyclohexylcarbonyl) peroxide and cyclohexane-1,2-dicarboxylic acid from aqueous solution affords stable 1-carboxycyclohexyl radicals, which were identified by EPR spectroscopy.

The decomposition of 2-chloro-, 2,2-dichloro-, and 2,6-dichloro-substituted cyclohexanone hydroperoxides on treatment with ferrous chloride and sulfate to give chloro-substituted aliphatic acids was investigated. A method for the synthesis of 2,6,6-trichlorohexanoic and 2,6,7,11-tetrachlorododecane-1,12-dioic acids was elaborated.

The reaction ofmeso- andD,L-forms of bis(cyclohexyl)-2,2′-dione with a methanol solution of hydrogen peroxide in a neutral medium has been studied. It has been established that in the case of theD,L-formrac-(1R,4R,9S,10S)-1,4-dihydroxy-2,3-dioxatricyclo-[8.4.0.04,9] tetradecane is formed, while themeso-form affordsrac-(1R,4R,9S,10R)-1-methoxy-4-hydroxy-2, 3-dioxatricyclo[8.4.0.04,9]tetradecane. The structures of the compounds have been established by X-ray structural analysis and by1H and13C NMR spectroscopy.

A convenient preparative synthesis of cilastatin, an inhibitor of renal dipeptidase used in drugs with the antibiotic imipenem, has been elaborated. The key intermediate in this synthesis is 2-amino-7-chloroheptanoic acid prepared by oxidative cleavage of cycloheptanone followed by bromination of 7-chloroheptanoyl chloride with subsequent amination of the 2-bromo-7-chloroheptanoic acid thus formed. All of the stages of the new synthesis are easily performed, as is the isolation of the intermediate products, and they do not require any organometallic reagents.

The decomposition of 1,4-dihydroxy-1,4-dihydroperoxycyclohexane under the action of FeSO4 and the decomposition of 1,4-cyclohexanedione monoethyleneketal hydroperoxide under the action of FeII salts in the presence of various ligands or under the action of CuII sulfate have been studied. A preparative method for the synthesis of derivatives of diketodicarboxylic or ω-functionally substituted ketocarboxylic acids from 1,4-cyclohexanedione monoethyleneketal has been developed.

A preparative method for the synthesis of α-haloadipic acids 4a-c by oxidative cleavage of 1,2-cyclohexanedione (1) in copper(II) halide/hydrogen peroxide or copper(II) halide (catalyst)/alkali metal halide/hydrogen peroxide system is reported

Hex-5-ynoic acid, a multipurpose synthon, was synthesized in three steps starting from cyclohexanone by bromination-dehydrobromination of the intermediate hex-5-enoic acid.

The reactivity of cyclohexanediones and their monoethylene ketals with hydrogen peroxide was studied. It was established that 1,2- and 1,3-cyclohexanediones virtually do not react with H2O2, whereas 1,4-cyclohexanedione forms 1,4-dihydroxy-1,4-dihydroperoxycyclohexane. Monoethylene ketals of cyclohexanediones react with hydrogen peroxide to form the corresponding α-hydroxy-α-hydroperoxides. The stereoelectronic factors determining the difference in reactivity of the carbonyl fragment in cyclohexanone, 1,2-cyclohexanedione, and its monoethylene ketal were analyzed within the framework of the semiempirical quantum chemical method MNDO.

A new route to diesters of symmetrical octene-, decene-, and dodecenedioic acids was proposed. The ratio of the cis/trans-isomers was 1: 4. The synthesis involved oxidative splitting of five-, six-, and seven-membered cycloalkanones with hydrogen peroxide into the corresponding ω-alkenoic acids followed by esterification and metathesis over Re2O7/B2O3-Al2O3-SnMe4.

A preparative method for the synthesis of α-haloadipic acids 4a-c by oxidative cleavage of 1,2-cyclohexanedione (1) in copper(II) halide/hydrogen peroxide or copper(II) halide (catalyst)/alkali metal halide/hydrogen peroxide system is reported

1. Oxidation of cyclohexanone by aqueous hydrogen peroxide at 110–150°C gives 1,10-decanedicarboxylic acid and hexanoic acid as the principal products. 2. Cyclopentanone and cycloheptanone react with hydrogen peroxide similarly to cyclohexanone, giving sebacic and pentanoic acids, and 1,12-dodecanedicarboxylic acids, respectively.

In the thermolysis of tricyclohexylidene peroxide in the liquid phase a “dilactone” is formed, besides the earlier identified macrocyclic compounds (cyclopentadecane and hexadecanolide), which is the cyclic ester of 1,10-decanedicarboxylic acid and 1,5-pentanediol.

1. The rate constant for the breakdown of the dimethyl ester of peroxydiglutaric acid (I) in benzene and toluene remains essentially unaltered as the pressure is raised to 10, 000 kg/cm2. 2. Breakdown of (I) can proceed with rupture of the O-O bond (ka) or with the rupture of three bonds and the evolution of two molecules of CO2 (kb). 3. Increasing the pressure increases proportion of radical reaction products formed through rupture of the O-O bond. 4. The rate constant kb, diminishes with rising pressure. 5. Increasing the pressure decreases the probability of radical reaction in the cage as compared with the probability of radical passage out of the cage.

Reaction of stoichiometric quantities of perfluorocyclohexanone and 98% H2O2 in neutral media quantitatively forms α,α′-dihydroxydi(perfluorohexyl)peroxide, for which the main crystal and molecular structural parameters were determined by x-ray analysis.

A mechanism was proposed for the selective oxidative cyclization of 3-carboxyprqpyl radicals to γ-butyrolactone when using the Na2S2O8-CuSO4 oxidation system. In this mechanism the Cu(III) ions take part in the reaction.

A new phenomenon, viz. the spontaneous formation of stabilized 1,2-dicarboxyethyl radicals in a crystalline matrix during the complete removal of the solvent from a solution of PDSA and SA in water, methanol, or acetone, was discovered.

1. The reaction of the esters of peroxydicarboxylic acids (CH3OOC(CH2)nCOO)2 with Fe(II) sulfate leads to the selective generation of ω-carbomethoxyalkyl radicals CH3OOC-(CH2)n, n=2-5, 7, 8, 10. 2. These radicals predominantly recombine under the influence of Fe(II) sulfate, while Cu(II) sulfate oxidizes them to the esters of the corresponding ω-unsaturated carboxylic acids, and Cu(II) chloride converts them to the esters of (ω-chlorocarboxylic acids.

1. The crystal structure and molecular structure of peroxydisuccinic acid have been determined. 2. Similarity has been found in most of the stereochemical parameters of peroxydisuccinic, succinic, and fumaric acids, and approximate isomorphism has been shown for the per-oxydisuccinic acid and the β-form of succinic acid. 3. On the basis of an analysis of the crystal and molecular structures of these compounds, a hypothesis has been advanced as to the stereochemical factors favoring inclusion of the peroxydisuccinic acid in the matrix of succinic or fumaric acid during cocrystallization, and also the factors destabilizing the peroxide group in these matrices and favoring its homolytic decomposition.

1. Ethyl pyruvate and levulinate react with an ether solution of hydrogen peroxide, forming α-hydroxy hydroperoxides CH3C(OH)(OOH)-(CH2)nCOOC2H5 (where n=0, 2); acetoacetic ester gives a mixture of α-hydroxy hydroperoxide (n=1) and α,α′-dihydroxy peroxide C2H5O2-CCH2C(OH)(CH3)-O-OC(OH)(CH3)CH2CO2C2H5. 2. During the decomposition of the α-hydroxy hydroperoxides by the action of ferrous sulfate and ferrous chloride the radicals ·(CH2)nCOOC2H5 (n=0, 1, 2) are generated selectively and enter into recombination, hydrogen transfer, and oxidation (when n=0) reactions.

1. New cyclic peroxydiacids were synthesized: peroxydi-cis-hexahydrophthalic, peroxydi-cis-Δ4-tetrahydrophthalic, and peroxydi-cis-endomethylene-Δ4-tetrahydrophthalic. 2. The thermal decomposition of peroxydiacids in acetic acid obeys a first-order equation with respect to the peroxide. As a result of the decomposition of the peroxydiacids, anhydrides are formed. A mechanism was proposed for their formation by cyclization of acyloxy radicals.

1. The thermal decomposition of peroxydisuccinic acid and its dimethyl ester was studied in acetic acid, benzene, and isopropanol. In benzene and acetic acid, a first order of the reaction with respect to the peroxide is observed. 2. Products of thermal decomposition of the peroxides were identified and a mechanism of their formation was proposed. 3. Radicals formed from peroxydisuccinic acid under the action of UV irradiation and as a result of secondary reactions in the absence of irradiation were investigated by the EPR method. A mechanism of photodecomposition with the participation of radical pair was proposed.

1. We synthesized the esters of some peroxydicarboxylic acids\({\text{CH}}_{\text{3}} {\text{OOC(CH}}_{\text{2}} {\text{)}}_n \mathop {\text{C}}\limits^{\mathop {{\text{||}}}\limits^{\text{O}} } {\text{OO}}\mathop {\text{C}}\limits^{\mathop {{\text{||}}}\limits^{\text{O}} } {\text{(CH}}_{\text{2}} {\text{)}}_n {\text{COOCH}}_{\text{3}} \), and determined the kinetic parameters of the reaction for their thermal decomposition in CH3COOH and benzene. The predominant generation of CH3OOC(CH2). n radicals occurs in the decomposition of the lower homologs (n=2,3), while the\({\text{CH}}_{\text{3}} {\text{OOC(CH}}_{\text{2}} {\text{)}}_n \mathop {\text{C}}\limits^{\mathop {{\text{||}}}\limits^{\text{O}} } {\text{O}}\) radicals are obtained mainly from the higher homologs (n=6,8). 2. A new homolytic cyclization reaction was discovered, namely the formation ofγ-butyrolactone from theγ-carbomethoxypropyl radicals that are obtained during the decomposition of the dimethyl ester of peroxydiglutaric acid.

1. The kinetics of the thermal decomposition of the dimethyl ester of peroxydiphthalic acid in acetic acid and benzene was studied. 2. The basic reaction products were identified, and the mechanism of their formation was proposed.

The action of catalytic amounts of copper ions in the presence of MX salts (M=K and Na, X=Cl, Br, I, SCN) leads to the decomposition of the hydroperoxides of C5-C7 cycloalkanones with the formation of ω-chloro-,ω-bromo-, ω-iodo-, and ω-thiocyanoalkanoic acids.

Reduction of cyclohexanoneα-hydroxyhydroperoxide by the action of an aqueous solution of FeSO4 in the presence of magnesium oxide is accompanied by the formation of 5-carboxypentyl radicals, which preferentially convert to hexanoic acid.

We have worked out a simple synthesis of 2-(ω'-carboxyalkyl)cycloalkanones, using as main starting materials cycloalkanones and hydrogen peroxide.

1. The 1,2,4-butane- and 1,2,5-pentanetricarboxylic acids were obtained via the addition of theβ-carboxyethyl andγ-carboxypropyl radicals to maleic acid. 2. Some g10 and C14 unsaturated dicarboxylic acids were synthesized by the addition ofβ-carboxyethyl radicals to butadiene. The relation between the yield of the products and the ratio of the reactants was determined.

1. 2-Carboxyethyl radicals add to the C=O group of aldehydes, with the formation of alkoxyl adduct-radicals that cleave H atoms from the aldehyde and are converted toγ-lactones. 2. 2-Carbomethoxyethyl radicals add to the C=O group of biacetyl and ethyl pyruvate, and the obtained adduct-radicals decompose to give methyl levulinate.

A synthetic method of preparing 5-bromopentanoic acid was develope by oxidation of cyclopentanone with aqueous solutions of H2O2. Subsequent decomposition of the resulting hydroperoxide of cyclopentanone was accomplished with a catalytic quantity of copper salt in the presence of alkali bromides.

Chemical polarization of protons was observed in methyl benzoate formed during the thermal decomposition of dimethyl ester of peroxydiphthalic acid. The polarization pattern of methyl benzoate aromatic protons was very different in this case from that observed during the thermal decomposition of acetyl benzoyl peroxide. The unpolarized products formed from the methoxy radical, CH2O and CH3OH, were found in the mixture of decomposition products of this peroxide and were identified by means of PMR spectroscopy.

1. 2-Carboxyethyl radicals, generated in the system peroxydisuccinic acid-Fe(III) sulfate, add to 1- alkenes. The intermediately formed adduct-radicals are oxidized by Fe(III) ions to give Δ4,5- and Δ5,6-alkenoic acids. 2. The vinyl adduct-radicals, obtained by the addition of 2-carboxyethyl radicals to 1-alkynes, predominantly cleave hydrogen from the H donor in the presence of Fe(III) ions. 3. α-Carboxyalkyl radicals are capable of being reduced by Fe(II) ions in water to the corresponding acids.

Reaction of stoichiometric quantities of perfluorocyclohexanone and 98% H2O2 in neutral media quantitatively forms α,α′-dihydroxydi(perfluorohexyl)peroxide, for which the main crystal and molecular structural parameters were determined by x-ray analysis.

The ω-olefincarboxylic acids (II), prepared from the cycloalkanones (I) by copper(II)/iron(II) sulfate-catalyzed oxidation with hydrogen peroxide, react with (I) in the presence of di-tert-butyl peroxide at elevated temperatures to give the title compounds (III).

Die Oxidation der Cycloalkanone (I) mit wasriger Wasserstoffperoxidlosung fuhrt zu Gemischen der Produkte (II)-(VIII).

A characteristic feature of liquid hydrocarbon decomposition in electric discharges is that considerable amounts of energy can be evolved in a small reaction space, with simultaneous quenching of the reaction products in the liquid medium. Under these conditions we can obtain gas with a high acetylene concentration (25–32 vol.%). When such processes are effected in unsteady electric discharges (as in the Tatarinov method [1]) the main electrodes and the intermediate current-conducting contacts undergo fairly considerable erosion, thus making it very difficult to obtain an appropriate layout of the apparatus. The use of a high-voltage arc [2,3] is accompanied by other difficulties because, owing to the high dielectric properties of the petroleum products cracked, it is difficult to employ discharge gaps permitting normal functioning of the process.

Most research on the decomposition of liquid organic substances in electrical discharges for the purpose of manufacturing acetylene has been concerned mainly with the design of the plant, the compositions and yields of the products from various types of feedstock, and the effects of the electrical characteristics on the yields and consumptions. Some interest also attaches to the changes which occur in the properties of liquids acted on by various types of electrical discharges. In most of the work so far done in this field [1–4], attention has been paid primarily to such properties as density, molecular weight, refractive index, fractionation properties, iodine number, total sulfonatables, etc. However, there are no data on the changes in the quantitative proportions of individual components in the hydrocarbon mixture.

Hex-5-ynoic acid, a multipurpose synthon, was synthesized in three steps starting from cyclohexanone by bromination-dehydrobromination of the intermediate hex-5-enoic acid.

A study was made of the effect of the salts FeSO4, MnSO4, and CoSO4 on the decomposition of peroxydisuccinic acid in aqueous medium. Both the composition and the yield of the reaction products are determined to a large degree by the nature of the metal ion.