Four eremophilanes have been isolated from the aerial parts of Senecio desfontainei, including a new one, 11-hydroxyeremophil-q7),9(10>dien-8-one [4]. The structures were established by high field nmr spectroscopy. The genus Senecio is rich in eremophilanes, furoeremophilanes, and pyrrolizidines, as well as other classes of natural products (1-4), and several compounds have been reported from Senecio desfontainei Druce (= S. coronopifolius Desf.) (Compositae) (5-7). Reinvestigation of this species afforded a new eremophilane 4, in addition to three previously reported compounds 1-3. The 'H-nmr data of 4 differed from those of 1-3; the downfield chemical shift of H-12 and H-13 at δ 1.46 and their presence as a singlet indicated that C-11 must bearing a hydroxyl function. This was verified by an ir absorption at 3550 cm-' as well as a 13C-nmr signal at δ 71.8 (C-11). Spin decoupling allowed the assignment of H-1, H-1', and H-4. The narrow doublet at δ 6.07 (H-9) showed a long range coupling with a multiplet at δ 2.37 (H-1), while irradiation of H-15 changed the signal at δ 1.56 (H-4). The mass spectrum exhibited peaks at m/z 234 for the molecular ion and at m/z 219 and 201 indicating loss of a methyl group followed by elimination of H2O. 13C-nmr data (see Experimental) also supported the proposed structure.