Diterpenoide Chinomethane, vinyloge Chinone und ein Phyllocladan‐Derivat aus Plectranthus purpuratus H ARV . (Labiatae)

Diterpenoids from Leaf Glands of Plectranthus purpuratus: p‐Quinomethanes, Extended Quinones, p‐Acylcatechols and a Novel Phyllocladanon Derivative From the complex mixture of terpenoids from the title plant, the following novel diterpenoids have been isolated: 11‐hydroxy‐19‐(3‐methyl‐2‐butenoyloxy)‐ and 11‐hydroxy‐19‐(3‐methylbutanoyloxy)‐5,7,9 (11), 13‐abietatetraen‐12‐one (1a/1b), 11‐hydroxy‐19‐(3‐methyl‐2‐butenoyloxy)‐ and 11‐hydroxy‐19‐(3‐methylbutanoyl‐oxy)‐7,9(11), 13‐abietatrien‐6,12‐dione (2a/2b), 6α, 11‐dihydroxy‐19‐(3‐methyl‐2‐butenoyloxy)‐ and 6α, 11 ‐dihydroxy‐19‐(3‐methylbutanoyloxy)‐7,9 (11), 13‐abieta‐trien‐12‐one (3a/3b), 11,12‐dihydroxy‐19‐(3‐methyl‐2‐butenoyloxy)‐ and 11,12‐di‐hydroxy‐19‐(3‐methylbutanoyloxy)‐8,11,13‐abietatrien‐7‐one (4a/4b), and (16R)‐17,19‐diacetoxy‐16‐hydroxy‐13β‐kauran‐3‐one (=(16R)‐17,19‐diacetoxy‐16‐hydro‐xyphyllocladan‐3‐one; 10). Compounds 2 and 3 are derivates of taxodione and taxodone, respectively, 4 is a derivative of cryptojaponol. The structure of 10 is Wised on a single‐crystal‐X‐ray analysis and CD. data.