Lactones dicarboxylic acid ester

ABSTRACT The review covers particularly the synthesis of fine chemicals via the formation of C-C bonds between carbon dioxide and hydrocarbons. In the reactions of CO2 with alkenes, dienes and alkynes a great number of carboxylic acids, dicarboxylic acids, esters, lactones and pyrones are formed, whether in stoichiometric or catalytic reactions. In each chapter the reactions are considered in the order of the transition metals applied. In addition, some syntheses will be mentioned which are closely related to transition metal catalysis, for instance the electrocarboxylation ofolefinic hydrocarbons. 

As a first approach to the synthesis of nagilactone 296, a norditer-penoid isolated from Podocarpaceae, which inhibit the expansion and mitosis of plant cells, an intramolecular Diels-Alder reaction of allene 1,3-dicarboxylic acid esters was used. The cyclization of 297 afforded the 8-lactone 298, rather than the y-lactone 299 [85JCS(P1)747]. 

The main aroma compounds identified as specific botrytized odorants are indicated in Table 6.6. It seems that while the terpene content decreases, numerous hydroxy-, oxo-, and dicarboxylic acid esters, acetals, and lactones form, all typically in lower concentrations or absent in normal wines (Miklosy and Kerenyi, 2004 Miklosy et al., 2000, 2004 Schreier et al, 1976). 

The nature of the Botrytis aroma compounds has been subjected to extensive research. In addition to the older findings about the importance of hydroxy-, oxo-, and dicarboxylic acid esters, acetals, and some special y- and 8-lactones, the role of volatile thiols has recently been elucidated. Nonetheless, additional research is needed to identify odor active compounds that are specific for botrytized wines. 

Lactones from dicarboxylic acid esters Stereospecific reaction... 

The benzoic acid derivative 457 is formed by the carbonylation of iodoben-zene in aqueous DMF (1 1) without using a phosphine ligand at room temperature and 1 atm[311]. As optimum conditions for the technical synthesis of the anthranilic acid derivative 458, it has been found that A-acetyl protection, which has a chelating effect, is important[312]. Phase-transfer catalysis is combined with the Pd-catalyzed carbonylation of halides[3l3]. Carbonylation of 1,1-dibromoalkenes in the presence of a phase-transfer catalyst gives the gem-inal dicarboxylic acid 459. Use of a polar solvent is important[314]. Interestingly, addition of trimethylsilyl chloride (2 equiv.) increased yield of the lactone 460 remarkabiy[3l5]. Formate esters as a CO source and NaOR are used for the carbonylation of aryl iodides under a nitrogen atmosphere without using CO[316]. Chlorobenzene coordinated by Cr(CO)j is carbonylated with ethyl formate[3l7]. 

The paraffin wax is oxidized by air in a liquid phase process at 110-130°C. Catalysts for this radical reaction are cobalt or manganese salts [54]. The quality of the obtained mixture of homologous carboxylic acids is impaired by numerous byproducts such as aldehydes, ketones, lactones, esters, dicarboxylic acids, and other compounds. These are formed despite a partial conversion of the paraffin and necessitate an expensive workup of the reaction product [50,55]. 

In vitro synthesis of polyesters using isolated enzymes as catalyst via non-biosynthetic pathways is reviewed. In most cases, lipase was used as catalyst and various monomer combinations, typically oxyacids or their esters, dicarboxylic acids or their derivatives/glycols, and lactones, afforded the polyesters. The enzymatic polymerization often proceeded under mild reaction conditions in comparison with chemical processes. By utilizing characteristic properties of lipases, regio- and enantioselective polymerizations proceeded to give functional polymers, most of which are difficult to synthesize by conventional methodologies. 

Heterocyclic secondary enamines and dicarboxylic acid dichlorides undergo complex, ring-size-dependent annulation reactions that, in the case of ester 238 and phthaloyl chloride (Scheme 57), lead to lactone-containing derivative 239 (02T2821). 

The ability to accept electrons from donors is particularly pronounced in acrylic acid derivatives [85] its alkyl esters [78, 87, 88], acrylonitrile [88], acrylamide, hydroxylacrylates [85], and further in styrenes substituted with an electronegative atom or group m-nitrostyrene, 2,6-dichlorostyrene [86], / -nitrostyrene [89] bicyclobutane-1-carbonitrile [89] lactones /J-propio-Iactone [85], sulfolactone vinyl ketones [87] unsaturated dicarboxylic acids and their derivatives diethyl fumarate, fumaronitrile [90], ROOC—N— N—COOR [86], cyclic anhydrides of diacids [91 ], particularly maleic anhydride [78, 92] ethylenes substituted with electronegative groups [93, 95]... 

Acetate esters are common by-products of LTA decaiboxylation procedures. The yield of these products, derived from further oxidation of the alkyl radical and quenching of the subsequent carbocation by acetate ions, can be improved by woiking in acetic acid in the presence of potassium acetate. Selective monodecarboxylation of 1,3- and 1,4-dicarboxylic acids leads, via an analogous mechanism, to y- and 8-lactones in moderate to good yields, as illustrated in equation (39). 

When the spiro-activated cyclopropane (479) is heated with aqueous acetone a 9 1 mixture of the lactone (482) and the dicarboxylic acid (480) is obtained. Thus, with water as a nucleophile, ring cleavage is faster than acylal cleavage. Presumably, the spiroacylal functions as an active ester in the cyclization of the initially formed 1,5-adduct (481) (equation 164) °. ... 

The modified Corey-Nicoiaou macroiactonization was applied for the construction of the BCD ring system of brevetoxin A by K.C. Nicolaou and co-workers. The dihydroxy dicarboxylic acid substrate was subjected to a one-pot bis-lactonization. After the formation of the bis-2-pyridinethiol ester, the lactonization was conducted at low substrate concentration (0.013 M) in toluene at reflux temperature. 

Benzo[c] cinnoline aldehydes are as yet unknown. The 2- and 3-acetyl derivatives have been prepared, but the majority of known compounds relevant to this section are mono- and dicarboxylic acid derivatives. These include the 2-, - - 3-, ° and 4. - o2.J55,i57 monoacids and esters, the lactone of 10-hydroxybenzo[c]cinnoline-l-carboxylic acid, some halogeno- and methyl-substituted 2- and 4. carboxylic acids, and the 2,9-, 3,8-, - - and 4,7- dicarboxylic acids and derivatives. These compounds have been obtained by ring synthesis, or, in the case of 2-methylbenzo[c]dnnoline-9-carboxylic acid, by side-chain oxidation, " rather than by the introduction of substituents into benzo[c] cinnoline. Benzo[c]cinnoline-l-carbonitrile has been prepared, albeit in low... 

The polyester polyols are obtained by the polycondensation reactions between dicarboxylic acids (or derivatives such as esters or anhydrides) and diols (or polyols), or by the ring opening polymerisation of cyclic esters (lactones, cyclic carbonates). 

---