Coleon-U-quinone

Abietanes.—A number of more highly oxygenated abietanes related to the royleanones have been described recently. A new quinone, nemorone (27), has been isolated from the roots of Salvia nemorosa. Coleon C (28) and its tautomer coleon D, which possesses a trans a/b ring junction and a 6,7-diketone in place of the diosphenol on ring b, have been isolated from Coleus aquaticus. These compounds have a very characteristic u. v. spectrum. Lycoxanthol is an ether (29) which has been isolated from Lycopodium lucidulum and which possesses a very similar structure. 

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