Structure of nimonol from fresh whole green leaves of Azadirachta indica

Nimonol was obtained from the fresh green whole leaves of Azadirachta indica and its structure has been reassigned on the basis of COSY, NOESY and 1H NMR spectral data. 6-Acetylnimonol was identified as 6-acetoxyazadirone and dihydronimonol was shown to be identical to isomeldenin. The mp and 1H NMR spectra of 6-acetylnimocinol were markedly different from those of 6-acetoxyazadirone showing that nimocinol and nimonol have different structures