Carboxylic acids acetone dicarboxylic acid

The first possibility is dubious, because there is no known biochemical oxidation reaction by which this would be accomplished. The other two possible pathways, acetone dicarboxylic acid or butyric acid, would both yield carboxyl-labeled acetoacetate, and thus 3,4-labeled glucose. The isolation of acetoacetate labeled only in the carboxyl group supports either possibility. An objection against the acetone dicarboxylic acid pathway is that acetoacetate, being a direct metabolic product of glutarate (see equation 6), should exhibit a higher specific activity than its resulting product, acetate. In the experiments of the above authors the specific... 

Dinitrocubane (28) has been synthesized by Eaton and co-workers via two routes both starting from cubane-l,4-dicarboxylic acid (25). The first of these routes uses diphenylphos-phoryl azide in the presence of a base and tert-butyl alcohol to effect direct conversion of the carboxylic acid (25) to the tert-butylcarbamate (26). Hydrolysis of (26) with mineral acid, followed by direct oxidation of the diamine (27) with m-CPBA, yields 1,4-diiutrocubane (28). Initial attempts to convert cubane-l,4-dicarboxylic acid (25) to 1,4-diaminocubane (27) via a Curtins rearrangement of the corresponding diacylazide (29) were abandoned due to the extremely explosive nature of the latter. However, subsequent experiments showed that treatment of the acid chloride of cubane-l,4-dicarboxylic acid with trimethylsilyl azide allows the formation of the diisocyanate (30) without prior isolation of the dangerous diacylazide (29) from solution. Oxidation of the diisocyanate (30) to 1,4-dinitrocubane (28) was achieved with dimethyldioxirane in wet acetone. Dimethyldioxirane is also reported to oxidize both the diamine (27) and its hydrochloride salt to 1,4-dinitrocubane (28) in excellent yield. ... 

Walther et al. improved the Na0Ph/C02 system by tuning the role of the solvent, such that the carboxylation of acetone was carried out selectively by sodium phenoxide with N-methyl-caprolactam under 0.1 MPa C02 to afford 3-ketoglutaric acid in 65% yield [34]. The same authors reported the conversion of acetyl-naphthalene (acetonaphthone) to acetyl-naphthalene carboxylic acid with 84% yield, and of cyclohexanone to cyclohexane-2,6-dicarboxylic acid in 56% yield. 

In an actual procedure, the carboxylic acid is reacted with an optically active a-methylbenzylamine to crystallize out the less-soluble salt in the quantities of about 50% of the whole diastereomeric salts. The double decompositions of both salts existing in the precipitate and mother liquor give the dicarboxylic acids of (+) and ( ) 60% ee, respectively. When these partially resolved carboxylic acids are recrystallized from water, the precipitated crystals are almost racemic, and the carboxylic acids of 88% ee remain in water. They can be converted into the corresponding acid anhydrides by the action of acetyl chloride. Acid anhydrides of almost 100% ee can be obtained by the recrystallization from acetone, after recovering the active acids from the mother liquor. Optically pure (+)- and (-)- ra .S -l,2-cyclohcxancdicarboxylic acids can be obtained by the hydrolysis of these anhydrides. 

The isolation of the silver carboxylates can be avoided. Stirring and refluxing a mixture of a diorgano tellurium dichloride, a carboxylic acid, and silver oxide in benzene or acetone gives diorgano tellurium dicarboxylates in good yields. Silver carboxylates were proposed as intermediates4. 

A number of reactions of metal salts can be rationalized in terms of the formation of a carbanion adjacent to the carboxylate. Dibasic metals such as calcium bring two carboxylate units close to each other so that the carbanion formed adjacent to one carboxylate may attack the carbonyl of the other. Thus pyrolysis of calcium acetate affords propanone (acetone) (Scheme 3.62). A similar reaction is found in the pyrolytic cyclization of some dicarboxylic acid anhydrides. Heating Cg and dicarboxylic acids gives cyclopentanones and cyclohexanones... 

The reaction was also performed in acetone in the presence of 5-10 equivalents of a carboxylic acid [52]. In this way, carboxylic acids which are solids can be employed. A number of different dicarboxylates were prepared in this manner from acetic acid, trifliioroacetic acid, pivalic acid, and benzoic acid. An example where the cis- and trans-1,4-dibenzoates from cyclohexa-1,3-diene were obtained stereoselectively is shown in Scheme 8-10. 

The 11-deoxyprostaglandins, a group not found in nature, have been synthesised by workers at the Ayerst Laboratories [115, 148-151]. 11-Deoxy-PGFy (LXXI) has been prepared starting from the enone (LXXII), obtained by the action of sulphuric acid on the monobromo derivative of the condensation product of ethyl 2-cyclopentanone carboxylate and (o-bromoethylheptanoate [115, 148, 149]. Reaction of (LXXII) with acetone cyanohydrin, hydrolysis of the ester-nitrile to the dicarboxylic acid and reaction with methanol and />-toluenesulphonic acid gave the mono ester (LXXIII) of which the acid chloride was converted with heptyne and aluminium chloride into the chlorovinylketone (LXXIV). The sequence was then completed by replacement of chloro with methoxyl, ester hydrolysis and borohydride reduction to the unsaturated ketone (LXXV) followed by borohydride reduction of the side chain carbonyl group. 

To 5a] In view of the behaviour of esters of pyrrole-dicarboxylic acids, already reported, it is interesting to notice that methyl pyrrole-2-carboxy-late undergoes alkaline hydrolysis considerably faster than the 3-isomer [10 A 2 (1. mole i sec ) (25°), 231, 4 1 and 0 59, for ethyl pyrrole-1-, and methyl pyrrole-2- and -3-carboxylate, respectively, in 56 per cent aqueous acetone]. The effect is attributed to intramolecular hydrogen bonding in the transition state (109)374 (cf. to c above). 

No pure tellurium derivatives were obtained when the sodium salts of maleic, fumaric, formic, isophthalic, or terephthalic acids were shaken with diaryl tellurium dichlorides2. Diorgano tellurium dichlorides stirred with silver carboxylates in dioxane, acetone, chloroform, benzene, or toluene precipitated silver chloride. Evaporation of the filtrate yielded diorgano tellurium dicarboxylates. 

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