New congeners of cytotoxic nor-diterpenoid dilactones in : three new components of 7,8-epoxy-enolide type

The Use of Carbon-13 Nuclear Magnetic Resonance Spectroscopy in Natural Products Chemistry

“…The Use ofCarbon-13 Nuclear Magnetic Resonance Spectroscopy 83 Structure (432) belonging to a group of meliacins, isolated from Khaya anlholheca heartwood, was derived from a comparison of its BC spectrum with those of the related systems cedrelone (433) and anthothecol (434) and their derivatives (130). The assignments of C-5 and C-6 in (433) and (434) are reversed by the present authors on the basis of the unique acetylation effect described for (416) (126).…”

Photolysis of the cyclooctadienyl anion

“…Examples are known in which enhanced basicity is observed in the excited state,1,5,6 and similar reactivity changes have been invoked to explain the photochemistry of cyclopentadienide7 and cyclononatetraenide.8 Fur- (7) Van Tamelen, E. E.; Brauman, J. I.; Ellis, L. E. J. Am.…”

The Chemistry of Bioactive Diterpenes

“…(5) can be extracted from the fresh root bark of Podocarpus nagi zoll [58]. (5) can be extracted from the fresh root bark of Podocarpus nagi zoll [58].…”