Itaconic anhydride, reactions

Itaconyl chloride has been prepared previously only by the reaction of itaconic anhydride with phosphorus pentachloride.4... 

The norbornene derivative 16, obtained exclusively as the exo adduct via a Diels-Alder reaction of itaconic anhydride with cyclopentadiene followed by hydrolysis and esterification [7], was found to be a suitable precursor for an enolate of type 14 (Scheme 2). Due to the quaternary center at C-3 eno-lization with base proceeded unambiguously, giving rise to a diastereomeric mixture of lactones 17/18 after reaction with hexanal. Retro-Diels-Alder reaction led to the monocyclic lactones 19/20 (2 1), elegantly unmasking the cxo-methylene group found in so many paraconic acids [8]. Hydrolysis of this mixture in refluxing butanone with 6 N HCl [9] effected epimerization... 

Two hundred grams of citric acid (0.95 mole) (Note 2) is placed in the reaction flask (Note 3) and heated with a free flame until melted. Then the flask is heated very rapidly with a large Meker burner, and the distillation is completed as rapidly as possible (ten to twelve minutes). Care must be taken to avoid superheating (Note 4). The distillate consists of water and itaconic anhydride, most of which distils at 175-190°. The distillate is immediately (Note 5) poured into a separatory... 

Magnesium perchlorate has been used as a catalyst for the synthesis of benzothiazepines 153 from chalcones and 2-aminothiophenol <07JHC541> while derivatives 154 using 3-cinnamoyl coumarin as the a,p-unsaturated ketone have also been synthesised <07JHC145>. The reaction of 2-aminothiophenol with itaconic anhydride also gives the benzothiazepine system 155 <07JHC457> while dibenzothiazepines 157 were formed by denitrocyclisation of the sulfide 156 <07JHC1247>. 

Diels-Alder reaction of itaconic anhydride with cyclopentadiene yields the adduct (49) which is converted into (50) (Scheme 1) for quantitative retro-Diels-Alder thermolysis to racemic ipsenol (51), reminiscent of the last steps of Mori s ipsenol synthesis (Vol. 6, pp. 18, 19). Both ipsenol (51) and the cor-... 

Formation of the corresponding a-substituted 5-lactams was accomplished by reaction of 296 with itaconic anhydride (316) to give dihydropyridone 317, 6 while pyridone formation was accomplished by aza-annulation with diester 47 to generate pyridone 318 (eq. 62).87... 

It has been also reported sicne 1958 [52] that itaconic anhydride (lAn), which is an another cyclic derivative of lA, polymerizes as well as other lA derivatives, but its reactivity is less than those of RII and RPhll. Poly(IAn) may be derived into some poly(IA) derivatives by reaction with amines and alcohols [63,64]. The polymerization reactivities of several itaconamides (lAm) and itaconamates (lAE) were also investigated [48]. It was found that iV, -dialkyl substituted lAm homopolymerize in the presence of a radical initiator, but iV,iV,iVj -tetraalkyl-substituted one did not give a polymer, because the latter consists of an a,7V, trisubsti-tuted acrylamide structure resemble to, y disubstituted methacrylamides. Similar results were obtained for polymerization of mono- and, V disub-stituted lAE. 

Poly((3-malic acid) is the most simple carboxylated polyester [47-49]. It is prepared by ring opening polymerization of the mono-benzyl ester (3-lactone of malic acid and subsequent debenzylation. It has been explored as drug carrier. Reaction of itaconic anhydride with PCL with hydroxy terminals results in polyesters with carboxylic and C=C double bond functional terminals, suitable for further reactions to form networks and gels, (5) and (6) [50,51]. 

Isopyrocalciferol, MA Diels-Alder adduct, 115 Isoquinoline MA adduct, 216 maleic acid reaction, 48, 216 Isosafrole, 375, MA Diels-Alder adducts, 118 Itaconic acid, MA copolymerization, 531, 660 haconic acid esters, preparation from succinates, 43 Itaconic anhydride... 

Some typical NMR spectra of ethylene propylene copolymers are shown in Figures 6.9 and 6.10. The technique has been used in various structural studies on copolymers. Thus Hashidzume and co-workers [61], in an investigation of the spontaneous copolymerisation of 2,6-diisopropyl-N-methylene aniline with phthalic anhydride or with itaconic anhydride, showed that in the case of polymerisation of 2,6-diisopropyl-N-methylene aniline and phthalic anhydride, the copolymer was formed by a coupling reaction of a zwitterion one to one adduct. Also in the case of copolymerisation of 2,6-diisopropyl-N-methylene aniline and itaconic anhydride, the copolymer is formed by the addition polymerisation through the C=C bond in the itaconic anhydride moiety. 

An interesting application of the retro-Diels-Alder reaction is provided by Rouessac and Haslouin in a new synthesis of the 1,3-diene ( )-ipsenol (70) (Scheme 29). Protection of the double bond of itaconic anhydride is achieved by formation of the cyclopentadiene adduct (68). Further synthetic elaboration gives (69) which affords ( )-ipsenol in quantitative yield on thermolysis at 450 °C. 

Condensation with Aldehydes and Ketones. Succinic anhydride and succinic esters in the presence of different catalysts react in the gas phase with formaldehyde to give citraconic acid or anhydride and itaconic acid (94—96). Dialkyl acyl succinates are obtained by reaction of dialkyl succinates with C 4 aldehydes over peroxide catalysts (97). 

One exception to the use of primary phosphines is in the reported syntheses of the catASium M dass of ligands 20 [46-49]. In one report, reaction of the cyclic sulfate with P(TMS)3 yields the TMS-protected secondary phospholane, which could then be reacted with the appropriate 1,2-dichloro spedes [46]. An alternative procedure to the same intermediate involves preparation of 1-phenyl-phospholane via the bismesylate, subsequent lithium-induced P-Ph deavage, and quenching with TMSC1 [49]. The ligand based on 2,3-dichloromaleic anhydride (20a originally referred to as MalPHOS [46]) has been shown to be effective for the chiral reduction of a- and /1-deliydroarnino acid derivatives and itaconate derivatives. 

Fumaric and itaconic acids are also used as the diacid component. Most reaction formulations involve a mixture of a saturated diacid (iso- and terephthalic, adipic) with the unsaturated diacid or anhydride in appropriate proportions to control the density of crosslinking (which depends on the carbon-carbon double-bond content of the prepolymer) for specific applications [Parker and Peffer, 1977 Selley, 1988], Propylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, and bisphenol A are also used in place of ethylene glycol as the diol component. Aromatic reactants are used in the formulation to improve the hardness, rigidity, and heat resistance of the crosslinked product. Halogenated reactants are used to impart flame resistance. 

Some thermosets are made with maleic anhydride only, or with other unsaturated 1,2-dicarboxylic acids or anhydrides such as itaconic acid or methylenesuccinic acid [7], chlorendic acid or 1,4.5,6,7,7-hexachloro-5-norbornene-2,3-dicarboxylic acid (or anhydride), 1,4.5,6,7-pentachloro-5-norbornene-2,3-dicarboxylic acid anhydride or 1,4.5,6-tetrachloro-5-norbornene-2,3-dicarboxylic acid anhydride. These norbomene derivatives can be obtained from the Diels-Alder condensation of the chlorinated cyclopenta-1,3-dienes and maleic anhydride, as shown in the following reaction ... 

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