1.7- Dihydroxy-3-methylxanthone

The new 3,6-dihydroxy-l,7-dimethoxyxanthone was identified in this plant together with the 5-chloro-l,6-dihydroxy-3-methoxy-8-methylxanthone, 1), 2), Fig.(15), which is the first chloroxanthone isolated from higher plants. 

In 1998, Fujimoto and co-workers reported the isolation of a novel nidulalin derivative, the l,9a-dihydro derivative of nidulalin A (888) (Fig. 13.8), along with the known compounds, emodin (791), and l,7-dihydroxy-3-methylxanthone, from the ascomycete Amxiella micropertusa (629). These authors also reported the isolation of this same compound in 2006, denoting it as GS-4 (888) (Fig. 13.8),... 

Dechlorothiomelin, l,8-Dihydroxy-2-chloro-5-methoxy-6-methyIxanthone (4-Dechlorthiomelin, l,8-Dihydroxy-2-chlor-5-methoxy-6-methylxanthon)... 

Methoxy-4-chloro-5,8-dihydroxy-6-methylxanthone (1 -Methoxy-4-chlor-5,8-dihydroxy-6-methylxanthon)... 

Santessson J (1970c) Syntheses of orsellinic acid and related compounds. Acta Chem Scand 24 3373-3378 Santesson J, Sundholm G (1968) Chemical studies on lichens. 14. Syntheses and chlorinations of norlichexanthone. Ark Kemi 30 427-431 Santesson J, Wachtmeister CA (1969) Chemical studies on lichens. 15. 2,4-Dichloro-6-methoxy-l,3-dihydroxy-8-methylxanthone (thiophaninic acid) from Pertusaria flavicans. Ark Kemi 30 445-448 Sargent MV (1980) Synthesis of grisa-2, 5 -dien-3,4 -diones by intramolecular ipsosubstitution. Chem Commim 285... 

Dihydroxy-5-methoxy-3-methylxanthone R - R" -H, R OMe, R "s OH yellow needles, mp214-215X... 

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