METABOLITES OF THE HIGHER FUNGI .29. MALDOXIN, MALDOXONE, DIHYDROMALDOXIN, ISODIHYDROMALDOXIN AND DECHLORODIHYDROMALDOXIN - A SPIROCYCLOHEXADIENONE, A DEPSIDONE AND 3 DIPHENYL ETHERS - KEYS IN THE DEPSIDONE BIOSYNTHETIC-PATHWAY FROM A MEMBER OF THE FUNGUS GENUS XYLARIA

-methoxycarbonylphenoxy)-6-hydroxy-4-methylbenzoic acid (dihydromaldox in 1), -methoxycarbonylphenoxy)-6-hydroxy-4-methylbenzoic acid (isodih ydromaldoxin 2), dechlorodihydromaldoxin 3, a new chlorinated depsidon e (maldoxone 4) and a new spirocyclohexadienone (maldoxin 5) have been isolated from the culture medium of an as yet unidentified Xylaria sp ecies, The structures have been determined by physical and chemical me thods and the positions of the substituents in dihydromaldoxin 1 have been confirmed by a single crystal X-ray structure determination, Thei r role in the grisan-depsidone biosynthetic pathway is discussed.