Methylene succinate

Stobbe was the first to observe photochromism in fulgides (1.33) when he synthesised them by the condensation of an arylaldehyde or ketone with a substituted methylene succinate. However, it was not until the 1970s, during the course of the extensive work carried out by Heller and his collaborators, that their chemistry and use in photochromism was truly exploited. Heller s work showed, amongst many other things, the importance of R in (1.33) being a 5-membered ring heterocycle, e.g. furan. 

Thermal cyclization of diethyl 2-[(2-quinolylamino)methylene]succinate (229) in boiling Dowtherm A gave ethyl 2-(l-oxo-l//-pyrimido[l,2-a]quinolin-2-yl)acetate (230) and a mixture of the isomeric l-(2-quinolyl)-5-oxopyrroline-3-carboxylates (231 and 232) [73GEP2315422 78... 

Fulgides are generally synthesized by a Stobbe condensation of aiyl aldehyde or ketone with a substituted methylene succinate, followed by hydrolysis and dehydration processes as shown in Scheme 1. 

Source Based on P. J. Darcy, R. J. Hart, and H. G. Heller, overcrowded molecules. Part 14. Photochromic systems involving (Z)-1 -methylpropylidene (diphenylmethylene)-succinic and (E)-3,5-dimethoxybenzylidene (alkyl- substituted methylene) succinic anhydrides, J. Chem. Soc., Perkin Trans. 1, 1978, 571-576. 

V. A. Kumar and K. Venkatesan, Studies on photochromism of a thermally stable fulgide in the crystalline state X-ray crystallographic investigation of (E)-2-isopropylidene-3-( 1-naphthyl methylene) succinic anhydride, Acta Cryst., B49, 896-900 (1993). 

The constitution of ita-conic acid as methylene succinic acid is thus established. Di-basic acids which contain a triple bond and, therefore, related to propin-oic acid are known but will not be considered. 

The compound itaconic add - or methylene succinate - is a substituted methacrylic add having the structural formula ... 

S. M. Aldoshin, L. O. Atovmyan, N. G. Furmanova, and O. A. Enikeeva. Stereospecific control of cyclization reaction of sterically overcrowded -benzylidene(diphenyl-methylene)succinic anhydride. Izv. Akad. NaukSSSR, Ser. Khim. 1986, 2063-2068. 

Itaconic acid (methylene succinic acid) is an unsaturated five-carbon dicar-boxylic acid. It is a by-product of the destructive distillation of citric acid. The reaction leading to itaconic acid from citric acid is as follows ... 

Among the other reduced prochiral substrates, methylene succinic acid was hydrogenated with ee values up to 59 and 50% using respectively the catalysts Rh-3 [3] and Ru-BINAP (9) [21]. The hydrogenation of the /hketo ester 21 was also performed in water in the presence of ruthenium complexes associated with ligands 13 and 14 (Eq. 4) [24, 25] the hydroxy ester 22 was obtained with enantioselectivi-ties up to 94%. 

A rhodium complex with chiral phosphane ligand was also intercalated into sodium hectorite by cation exchange (Sento et al. ). The intercalated compound was characterized by FTIR, XRD, and TEM and the basal spacing of the compound was estimated to be 2.29 nm. This novel het-erogenized eatalyst exhibited a characteristic chiral as well as size recognition of the substrate molecule (like the "Tailor-made compounds" method used earlier by Balandin in the hydrogenation of tripticene derivatives over Ni) and was used in enantioselective hydrogenation of the itaconates (methylene-succinic acid esters). 

Butyne-l,4-diol derivatives undergo dicarbonylation of different types. A simple synthetic method of bis(methylene)succinate 78 is the carbonylation of the dicarbonate of but-2-yne-l,4-diol (77) at 50°C [20]. 

Others contain semi-rigid backbone structures as in the case of the itaconic acid (methylene succinic acid) (2). 

Also called methylenebutanedioic acid and methylene-succinic acid. 

Itaconic Acid (Methylene-succinic acid, pro-pytay -2 -dicarbozyUc acid)... 

Yoo ES, Im SS (1999) Effect of crystalline and amorphous structures on biodegradability of poly(tetra methylene succinate). J Environ Polym Degrad 7 19-26... 

Conformational studies on poly(decamethylene adipate) and poIy(tetra-methylene succinate) and the use of molecular orbital theory potential energy surfaces in determining polymer conformations for 2GT have also appeared. Crystallization, Crystallinity, and First and Second Order Transition Behaviour. The crystallization behaviour of 2GT, alone or in admixture with additives or modified by small amounts of co-monomers, continues to evoke considerable interest. Thus, X-iay fluorescence studies have been made on phenylmercurated... 

Since polymerizations of maleic acid and various alkyl esters were mentioned earlier, the derivatives of maleic add discussed below are fumaric acid and dialkylfumarates, maleonitrile and fumaronitrile, maleimide and its N-substituted derivatives, and methylene succinic acid and its anhydride (itaconic anhydride). 

Merck and Company, Whitehouse Station, NJ, 2001). Also called Methylenebutanedioic Acid and Methylene-Succinic Acid. 

Darcy, P.J., Heller, H.G., Strydom, P.)., and Whittall, J. (1981) Photochromic heterocyclic fulgides. Part 2. Electro-cyclic reactions of (e)-2, 5-dimethyl-3-furylethylidene(alkyl-substituted methylene)succinic anhydrides. J. 

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