Recherches sur la biochimie des champignons inférieurs VIII . Synthèse chimique de pigments diquinoniques

New simplified syntheses of two natural p ‐diquinonic pigments, phoenicine and oosporeine, have been described. By similar procedures, the syntheses of two other related diquinones have been carried out: 3,3′,6,6′‐tetrahydroxy‐biphenyl‐di‐ p , p ′‐quinone and 3,3′,6,6′‐tetrahydroxy‐4‐methyl‐biphenyl‐di‐ p , p ′‐quinone. The latter structure had been assigned to pyxiferine, which had been reported to be contained in the lichen Pyxine coccifera .