Leprapinic acid methyl ether

Deriv Leprapinic acid methyl ether, needles... 

Only two terphenylquinones, polyporic acid and thelephoric acid, are known, while pulvinic acid derivates are more numerous (calycin, epanorin, leprapinic acid, leprapinic acid methyl ether, pinastric acid, pulvinic acid, pulvinic dUactone, rhizocarpic acid, stictaurin, vulpinic acid). 

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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