Dimethylmaleic anhydride, photocycloaddition

Photocycloadditions of maleic anhydride and dimethylmaleic anhydride to various other substituted cyclohexadienes and to cycloheptatriene have also been reported/58,97 98 ... 

Acetone-sensitized [2+2]-photocycloaddition of 2(3//)-oxazolones 247a to maleic anhydride and dimethylmaleic anhydride gives the corresponding anti-cyclobutane cycloadducts 253 as the major products. Similar photoreaction of 2(37/)-oxazolones with 1,6-anhydro-4-(9-benzyl-2,3-dideoxy- 3-D-e 7t/ira-2-hex-enopyranose 254 results in the exclusive formation of the anh-cyclobutane-type adduct 255 (Fig. 5.61). ... 

Other five-membered heterocyclic enones used in [2 + 2] photocycloadditions are 1//-pyrrole-2,3-diones86-88 and derivatives of maleic anhydride. Some cycloadducts of dimethylmaleic anhydride and unsaturated acid esters have been used as monomers for condensation polymers.89... 

Dimethylmaleic anhydride undergoes benzophenone-sensitized photocycloaddition to benzo[b]selenophene in benzene solution to give (70), and under comparable conditions the selenophthenes (71) and (72) give 1 1 and 2 1 [e.g., (73) and (74)] adducts.Neckers and co-workers have contributed many... 

A (2 + 2)-photoadduct is formed on irradiation of 2,3-dimethylmaleic anhydride with 3,4-dimethyl-1-phenylphosphole. " The photocycloaddition of maleic anhydride derivatives (124) to the alkene moiety in (125) affords the adducts (126) by a straightforward (2 + 2)-addition. The (2 + 2)-photoadducts (127) are readily produced by the dimerization of the corresponding maleic anhydrides in ethyl acetate solution.The intramolecular photochemical cyclization of the succinimide derivative (128) is a key step in the new synthetic approach to the tetracyclic fragment of neotuberostemonine. ... 

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