SPECTRAL PROPERTIES OF RING-C-OXYGENATED 4-AZAFLUORENES AND 4-AZAFLUORENONES. THE STRUCTURES OF NATURAL ONYCHINE DERIVA TIVES

We are graleful lo Dr D. Davousl for lhe 500 MHz lH nmr spectra and Dr l.A. Pinheiro for work al 200 MHz. D.T. was supported in part by a fellowship from the French government.