Cycloalkane-1,2-dicarboxylates

Formation of cycloalkane-1,2-dicarboxylate esters by reduction of dibromoalkanedicarboxylate esters at a platinum cathode in tetrahy-drofuran. Data from ref. [109]... 

The procedure described here provides a simple and general method for the construction of optically active trans-cycloalkane-1,2-dicarboxylic acids. The reaction has been applied successfully to a series of dihalides and ditosylates (Table). 

The stereoselective hydrolysis of dimethyl esters of symmetrical dicarboxylic acids including mesodiacids such as cw-1,2-cycloalkane dicarboxylic acids and diacids with... 

In the first reports by Ishii and coworkers , catalytic amounts of both HPI and Co(II)acetylacetonate, Co(acac)2, were employed for the oxidation of alkanes in AcOH at 100 °C, dioxygen being the terminal oxidant. The appeal of this procedure for the oxidative transformation of simple hydrocarbons into carbonyl derivatives is clear. Cycloalkanes were converted into a mixture of cyclic ketones plus open-chain a, )-dicarboxylic acids (Table 11), while linear alkanes yielded the corresponding alcohols plus ketones in significant amounts (40-80%), and alkylbenzenes could be oxidized in almost quantitative yields . 

The acyloin condensation was used in an ingenious manner to prepare the first reported catenane (see p. 91).727 The catenane (39) was prepared by a statistical synthesis (p. 91) in the following manner An acyloin condensation was performed on the diethyl ester of the C34 dicarboxylic acid (tetratriacontandioic acid) to give the cyclic acyloin 37. This was reduced by a Clemmensen reduction with DCI in D20 instead of HC1 in H20, thus producing a C34 cycloalkane containing deuterium (38) 728... 

Under the standard reaction conditions (no sodium acetate), the cyclic olefins tested afforded predominantly diesters with the exception of cyclohexene which gave a low yield of /3-methoxy ester (Table II). In each case, the cycloalkane 1,2- and 1,3-dicarboxylic esters obtained were the cis isomers. The relative rates of diester formation show the... 

Dehydrohalogenation sometimes leads to cyclization which gives cycloalkanes or heterocycles. The fluorinated diester 1 has proved to be a convenient source of polyfluoroalkylated cyclopropanes. Reaction of 1 with aqueous potassium hydroxide gives 2- HA //-hepta-fluorobutyl)cyclopropane-l, 1 -dicarboxylic acid (2) in quantitative yield.120 The diethyl ester 3 ot this acid is obtained in a yield of 87% by the reaction of 1 with sodium ethoxide in anhydrous ethanol.120... 

Cyclic olefins preferably undergo twofold carbonylation, even without the presence of buffer compounds such as sodium acetate. With methanol serving as the solvent and under comparable reaction conditions to those mentioned above, cycloalkenes give product mixtures consisting of methyl rrans-2-methoxy-cycloalkanecarboxylates, dimethyl cw-cycloalkane-l,2-dicarboxylates and dimethyl cw-cycloalkane-1,3-dicarboxylates (eq. (3) and Table 1). The formation of 1,3-diesters may be explained by an intermediate reaction sequence which involves an oxidative elimination and a subsequent readdition of the Pd species, thus giving rise to an isomerization [9]. 

Other examples of nitroxyl radicals such as TEMPO [3Id, j] have been used successfully in several examples of environmentally friendly liquid-phase oxidations with. oxygen. Sheldon et al. have reported on the use of N-hydroxysaccharin as an alternative to NHPI in the oxidation of cycloalkanes to dicarboxylic acids [31h]. Other examples include the aerobial oxidation in the presence of NHPI, o-phenanthroline and bromine, in an acetonitrile/CCU solvent and in the absence of metals, at 100 °C. The selectivity was 75% to AA and 22% to cyclohexanone, at 48% cyclohexane conversion [31i]. 

Dimeric copper caprate is responsible for the ability of capric acid to extract copper(ii) in organic solvents. Ternary complexes of copper(i) with bipy and cycloalkane-1,1-dicarboxylic acids, Cu(A)(B), are blue and contain NjOj co-ordination. Copper(ii)-edta complex solutions have much higher intensities in v(M—O) and v(M—N) than those of other metals. ... 

Cycloalkanes are generally oxidized to straight-chain dicarboxylic acids only with great difficulty and then in poor yield. For example, on oxidation by nitric acid cyclohexane gives a mixture of 29% of adipic acid and 36% of nitrocyclohexane.101... 

N-condensed 19, 463 cycloalkane-1,3-diones, 2-acyl- 19, 841 dicarboxylic acid chloride esters 17, 619... 

The pKj values of a homologous series (C - C ) of cyclopentyl and cyclohexyl carboxylic acids obtained at 298 K by titration have been reported and are just as expected. The proton ionization of cycloalkane-l,l-dicarboxylic acids in aqueous perchloric acid or sodium perchlorate solutions has also been studied. From the data obtained it is suggested that the solvent-solute interactions present can be related to the conformational features of the acids. 

Gycloalkane-l,2-dicarboxylic acids via cycloalkane-1,1,2,2-tetracarboxylic acid esters CIS- from trans-Dicarboxylic acids via cis-dicarboxylic acid anhydrides... 

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