Pulvinic anhydride

Olefination reactions of the phosphonates (254) and (255) derived from hydantoin and 1-methylhydantoin, respectively, provide good yields of the expected C-5 unsaturated hydantoin derivatives (256), generally as mixtures of isomers. 52 Heterocyclic analogues, e.g. (257), of pulvinones and, e.g. (258), of permethylated pulvinic acids have been synthesized by Wadsworth-Emmons reactions of the phosphonates (259) and (260), themselves prepared directly from substituted maleic anhydrides. 55 The reaction of ylide (261) with aldehydes to give (262) has been used as a key... 

Patenden et al. [46] synthesized heterocyclic analogues of pulvinones 52-55 and of permethylated pulvinic acids 56, 57 which were found in higher fungi (Scheme 21). All compounds possessing lactonic structures were synthesized in the Horner-Wittig reaction using the corresponding heteroaryl aldehydes and 4-dimethoxy-phosphorylated lactone 58. The latter was obtained as the main product in the reaction between substituted maleic anhydrides 59 and sodium dimethyl phosphite via the postulated carbene. 

Dilactones. Polyporic acid allowed to react 15 min. at 60° with a 1 2 mixture of acetic anhydride and dimethyl sulfoxide pulvinic acid dilactone. Y 90%. F. e. with monohydroxyquinones s. H. W. Moore and R. J. Wikholm, Tetrah. Let. 1968, 5049. 

Symmetrically substituted pulvinic dilactones are conveniently obtained from terphenylquinones by oxidative ring cleavage. This may be brought about with hydrogen peroxide 425), with lead tetra-acetate 248) or best with dimethyl sulphoxide and acetic anhydride 493, 715). Because of the ease with which terphenylquinones themselves may be derived by methoxide catalysed rearrangement of grevilhns 462)... 

Edwards, R. L., and M. Gill Constituents of the Higher Fungi. Part XIII. 2-Aryl-3-methoxymaleic Anhydrides from Pulvinic Acid Derivatives. A Convenient Method for Determination of Structure of Fungal and Lichen Pulvinic Acid Derivatives. J. Chem. Soc. (London) 1534(1973). 

Fully methylated pulvinic acid derivatives are cleaved by alkali to 2-aryl-3-methoxymaleic anhydrides and arylacetic acids (see Scheme 169). The products formed indicate the structure of the particular pulvinic acid (184). By reaction of vulpinic acid with 2-hydroxy-ethoxyacetamide a mixture of pulvinic acid monolactam (547) and pulvinic acid dilactam (548) (see Scheme 170) has been obtained (65(5). Further new pulvinic acid derivatives are vulpinic acid isopropyl ether (549) (660) and the pyridazine 550 (600) (see Schemes 171 and 172). Chawla et al. (67) investigated the photochemical conversion of pulvinic add to leprapinic acid. 

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