The absolute configuration of 3 was determined using Mosher's method. The obtained Δδ SR values for 3 (Figure ) revealed a similar pattern to those calculated for 2 consistent with an identical absolute configuration for 3 of (4R,5R,7S,10R and 136.2 (C-8) suggesting their existence as an α,β-unsaturated ketone moiety. Moreover, the 1 H NMR data of 4 (Table ) also revealed the presence of an oxygenated aliphatic methine proton at δH 3.49 (H-1) that was illustrated by 1 H-1 H COSY spectrum (Figure ) to form a spin system with two diastereotopic methylene groups at δH 1.78/δH 1.86 (H2-2) and δH 1.72/δH 1.95 (H2-3). This suggested that the additional hydroxy group is attached to C-1 of ring A. In addition, H NMR and HSQC spectra of 4 also revealed the presence of a deshielded methylene group at δH 4.16 (H2-11;