Cyclic acid anhydride

After acyl halides acid anhydrides are the most reactive carboxylic acid derivatives Three of them acetic anhydride phthahc anhydride and maleic anhydride are mdus trial chemicals and are encountered far more often than others Phthahc anhydride and maleic anhydride have their anhydride function incorporated into a nng and are referred to as cyclic anhydrides... 

Hydrolysis (Section 20 6) Acid anhydrides react with water to yield two carboxylic acid func tions Cyclic anhydrides yield di carboxylic acids... 

Acid Anhydrides. Symmetrical anhydrides of monocarboxylic acids, when unsubstituted, are named by replacing the word acid by anhydride. Anhydrides of substituted monocarboxylic acids, if symmetrically substituted, are named by prefixing bis- to the name of the acid and replacing the word acid by anhydride. Mixed anhydrides are named by giving in alphabetical order the first part of the names of the two acids followed by the word anhydride, e.g., acetic propionic anhydride or acetic propanoic anhydride. Cyclic anhydrides of polycarboxylic acids, although possessing a... 

Compared with standard diglycidyl ether resins, the liquid cyclic aliphatic resins are paler in colour and have a much lower viscosity. Whereas in general the cyclic aliphatic resins react more slowly with amines, there is less difference with acid anhydrides. Table 26.7 provides data illustrating this point. 

Symmetrical anhydrides of unsubslituted monocarboxylic acids and cyclic anhydrides of dicarboxylic acids are named by replacing the word acid with anhydride. 

Cyclic acid anhydrides are highly reactive not only to electrophilic attack but also to nucleophilic attack. Alternating copolyesters were obtained from cyclic acid anhydrides and epoxides at high temperatures261-263. ... 

The scope of this reaction is similar to that of 10-21. Though anhydrides are somewhat less reactive than acyl halides, they are often used to prepare carboxylic esters. Acids, Lewis acids, and bases are often used as catalysts—most often, pyridine. Catalysis by pyridine is of the nucleophilic type (see 10-9). 4-(A,A-Dimethylamino)pyridine is a better catalyst than pyridine and can be used in cases where pyridine fails. " Nonbasic catalysts are cobalt(II) chloride " and TaCls—Si02. " Formic anhydride is not a stable compound but esters of formic acid can be prepared by treating alcohols " or phenols " with acetic-formic anhydride. Cyclic anhydrides give monoesterified dicarboxylic acids, for example,... 

So far, various dicarboxylic acid derivatives, dicarboxylic acids, their activated and non-activated esters, cyclic acid anhydrides, and polyanhydrides have been polymerized with glycols through lipase catalysis to give polyesters. 

Reactions with Acylium Ions. Alkenes react with acyl halides or acid anhydrides in the presence of a Lewis acid catalyst to give (3,y-unsaturated ketones. The reactions generally work better with cyclic than acyclic alkenes. 

Various combinations of dicarboxylic acid derivatives and glycols enzymatically afforded polyesters under mild reaction conditions. Dicarboxylic acids as well as derivatives, activated and non-activated esters, cyclic acid anhydride, and polyanhydrides, were found to be useful as monomer for the enzymatic synthesis of polyesters. 

Pyrrole is one of the most prominent heterocycles, having been known for more than 150 years, and it is the structural skeleton of several natural products, synthetic pharmaceuticals, and electrically conducting materials. A simple access to the pyrrole ring system involves the conversion of cyclic anhydrides into five-membered imides. Mortoni and coworkers have described the conversion of 2-methylquinoline-3,4-dicarboxylic acid anhydride to a quinoline-3,4-dicarboximide library by treatment of the anhydride with a diverse set of primary amines under microwave conditions (Scheme 6.180) [341]. The authors studied a range of different conditions, including dry media protocols (see Section 4.1) whereby the starting materials were adsorbed onto an inorganic support and then irradiated with microwaves. For the transforma-... 

Reactions of titanocene-methylidene generated from titanacyclobutanes with acyl chlorides 55 [46] or acid anhydrides 56 [47] lead initially to the titanium enolates 57 (Scheme 14.24), which then afford aldols upon treatment with the carbonyl compounds. On the other hand, five-membered cyclic anhydrides are methylenated with dimethyltitanocene (Table 14.5, entry 7) [45]. 

Cyclic acid anhydrides such as maleic, dodecylsuccinic, hexahydrophthalic, phthalic, phyromellitic, etc. are widely employed as curing agents for epoxy resins. They form esters with epoxy resins. These resins have better thermal stability and good electrical insulation and chemical resistance expect to alkalis. 

K. Yamamoto, T. Nishioka, J. Oda, Y. Yamamoto, Asymmetric Ring Opening of Cyclic Acid Anhydrides with Lipase in Organic Solvents , Tetrahedron Lett. 1988, 29, 1717-1720. 

Blanc rule org chem The rule that glutaric and succinic acids yield cyclic anhydrides on pyrolysis, while adipic and pimelic acids yield cyclic ketones there are certain exceptions. blar k, rul ... 

The unlikely molecule in Figure 20—1 is a cyclic anhydride known by several names 2-butene-1,4-dicarboxylic acid anhydride cis-butene-dioic acid anhydride maleic anhydride (MA) and when youVe been in the business a long time, maleic. ... 

The replacement of ring C by a cyclic anhydride ring could be looked upon either as elimination of ring C or replacement of the ring by a heterocyclic anhydride ring. In any case, Fields et al. showed that quinolizinium 2,3-dicarboxylic acid anhydride (37) underwent cycloaddition reactions with either cyclopentadiene or styrene to alFord the expected products (e.g., 38). The 2,3-dimethylquinolizinium ion did not undergo cycloaddition even with the more reactive ketene diethylacetal. 

Procedure for ASD of a cyclic meio-anhydride using (DHQD)jAQN as catalyst ASD of cis-cyclopentane-l,2-dicarboxylic acid anhydride [208-210]... 

Lenchs anhydride Cyclic anhydride that decomposes to carbon dioxide and an amino acid. 

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