E. K. Starostin

Synthesis of ω-haloalkanoic acids by the catalytic decomposition of cycloalkane hydroperoxides by copper ions

ConclusionsThe 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.

Synthesis of unsaturated dibasic acid esters from five-, six-, and seven-membered cycloalkanones

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.

Synthesis of ω- and (ω – 1)-acetylenic acids from five-, six-, or seven-membered cycloalkanones

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.

Reaction of stereoisomeric bis(cyclohexyl)-2,2′-diones with hydrogen peroxide: structure of the formed adducts

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.

Practical synthesis of hex-5-ynoic acid from cyclohexanone

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.

Oxidative cleavage of cycloalkanones by hydrogen peroxide

Conclusions1.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.

A new approach to the synthesis of cilastatin, an inhibitor of renal dipeptidase

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.

Synthesis of 5-bromopentanoic acid through catalytic decomposition of the hydroperoxides of cyclopentanone

ConclusionsA 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.

Crystal structure of peroxydisuccinic acid

Conclusions1.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.

Decyclization of chiorocyclohexanone hydroperoxides under the action of ferrous salts

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.