TUMOR INHIBITORS .48. TAXODIONE AND TAXODONE, 2 NOVEL DITERPENOID QUINONE METHIDE TUMOR INHIBITORS FROM TAXODIUM DISTICHUM

Evidence is presented for assignment of structure for two novel tumor-inhibitory diterpenoid quinone methides from Taxodium distichum, taxodione (I) and taxodone (6). The structures were deduced from studies of their infrared, ultraviolet, nmr, and mass spectra and confirmed by interrelation with a known diterpene. Both quinone methides were converted to 11,12-dihydroxyabieta-8,11,13-trien-6-one (2), which was methylated to 11,12-dimethoxyabieta-8,11,13-trien-6-one (4). Reduction of 4 with lithium aluminum hydride gave the 6β-alcohol 5, which was dehydrated to 11,12-dimethoxyabieta-5,8,11,13-tetraene (7). Catalytic hydrogenation of 7 gave 11,12-dimethoxyabieta-8,11,13-triene (8), characterized by direct comparison with a sample prepared from sugiol (9). The third new compound isolated from T. distichum, taxoquinone, has been assigned the 7β-hydroxyroyieanone structure 13. In addition, the isolation of the known diterpenes royleanone (12), sugiol (9), and Δ5-dehydrosugiol (15) is described. © 1969, American Chemical Society. All rights reserved.