Cyclic carboxylic acids

Transition metal-mediated C-C bond formation through reaction of C02 with acetylenes and dienes can serve as a useful method for the construction of various carbon skeletons, such as linear and cyclic carboxylic acids, and esters and lactams. Enantioselective incorporation of C02 can also be achieved, especially when combined with sterically controlled formation of cyclic carbo- or heterocyclic skeletons. In perspective of the future in this area, development of more efficient and more selective catalytic systems for incorporation or transformation of C02 into useful fine chemicals and polymer materials will continue to be an important and attractive research target. 

Fermi resonances of the v0H=l state with over- and combination tones of modes in the fingerprint region are considered a key element determining the spectral envelope of the O-H stretching bands of cyclic carboxylic acid dimers. In principle, such Fermi resonances open up channels for population relaxation of the O-H stretching modes through the O-H bending... 

What procedures arc available for producing an aliphatic cyclic carboxylic acid ... 

Cyclic carboxylic acids are more acidic than their acyclic analogues. 

For cyclic carboxylic acid derivatives, decreasing ring size shifts a carbonyl absorption to higher frequencies. 

Several related reactions involve reduction of cyclic carboxylic acid derivatives to masked aldehydes which resist further reduction but can be converted into the required aldehydes by acid hydrolysis. In a series of papers, it was established that carboxylic acids could be converted into dihydro-1,3-thiazines or dihydro-1,3-oxazines which could be reduced by NaBH4 in weakly acidic ethanol. Thus, as shown in Scheme 20, dihydro-1,3-thiazines (41) were reduced to tetrahydro-1,3-thiazines (42) in yields of 66-84%. The resulting tetrahydro compounds could be hydrolyzed to aldehydes by aqueous acid. - In a later publication, these workers showed that there was little evidence for ring opening during reduction and that other methods of reduction e.g. hydrogenation over Pt, Pd or Rh or use of dissolving metals such as Zn, Sn or Na) were totally unsuccessful. In closely similar work, reduction of 5,6-dihydro-4W-... 

Table 6 Cyclic Carboxylic Acid Anhydrides Reduced to the Corresponding Aldehydic Acids by Na2[Fe(CO)4] ...

Band Width. The structure of has been discussed at length in Chapter 3 (Section 3.3.8). As indicated there, one of the currently popular theories is based on the assumption of extreme mechanical anharmonicity of Vi (268, 724, 1). The theory is well described (268), and will not be reproduced here in view of the experimental evidence concerning the anharmonicity presented in Section 3.3.9. Of particular interest are the remarks in that section referring to the absence of odd power terms in the potential function for the IR-active Vg mode of a cyclic carboxylic acid dimer. The implication which can be drawn is that the anharmonicity of this vibration may be quite low. Since an explanation of the extreme band-widths must encompass the carboxylic acids (see Fig. 3-20), anharmonicity does not seem to be a likely one. The weight of evidence suggests that Vg is not unusually anharmonic. 

Scheme 55. Formation of cyclic carboxylic acid derivatives by enyne cycloisomerization and CO2 insertion at Ni(0).

Cycloalkanecarboxylic acid A saturated cyclic carboxylic acid. 

Cycloalkane An alkane whose carbons form a ring, also called a cyclic alkane or carbocycle. Cydoalkanecarboxylic acid A saturated cyclic carboxylic acid. 

Also, in 1999, Mitsubishi Chemical Corporation discovered that the addition of cyclic carboxylic acid anhydrides, such as succinic anhydride (18) and maleic anhydride (19), suppresses the decomposition of PC even when graphite anodes are used [56],... 

Identify the longest chain of carbon atoms that contains the carboxyl group to determine the root name.The suffix -e is then changed to -anoic acid. For cyclic carboxylic acids, carboxylic acid is appended to the name of the cycloalkane (without dropping the suffix -e). As usual, remember to note stereochemistry (E/Z, cis/trans, or R/S) where appropriate. 

III) tricarboxylate salts. Cyclic carboxylic acid anhydrides, for example, phthalic anhydride, give polyesters with PO. The reaction is catalyzed by diethyl zinc, lithium chloride, tertiary amines, and quaternary ammonium halides. 

Synthesis of Cyclic Carboxylic Acid Anhydrides Succinic Anhydride and Phthalic Anhydride... 

Purpose. One of the important methods for preparing cyclic carboxylic acid anhydrides is carried out. The reaction demonstrates the use of acetic anhydride, an important industrial and research chemical, as a dehydrating agent. 

Also, bis-1,3-dienes incorporate carbon dioxide in the presence of Ni(acac) and a diorganozinc reagent to afford cyclic carboxylic acids °. Conjugated dienemagnesium reagents react with acetone at -78 °C, followed by carbon dioxide at 0°C to form the spiro-y-lactone 34 in 68 % yield. ... 

Aluminum chloride/hydrogen chloride Cyclic carboxylic acids from lactones... 

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