(4bS,8aS)-1-Isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a,9,10-octa-hydro-phenan-thren-2-yl benzoate

The title compound, C27H34O2, was hemisynthesized through direct benzoyl-ation of the naturally occurring meroterpene totarol. The central fused six-membered ring has a half-chair conformation, whereas the terminal six-membered ring displays a chair conformation. The dihedral angle between the fused benzene ring and the benzoyl benzene ring is 73.05 (14)°. The S,S chirality of the mol-ecule is consistent with the synthetic pathway, and confirmed by the refinement of the Flack parameter.

(4bS,8aS)-1-Isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a,9,10-octa-hydro-phenan-thren-2-yl acetate

The hemisynthesis of the title compound, C₂₂H₃₂O₂, was carried out through direct acetyl­ation reaction of the naturally occurring diterpene totarol [systematic name: (4bS,8aS)-4b,8,8-trimethyl-1-propan-2-yl-5,6,7,8a,9,10-hexa­hydro­phen­an­thren-2-ol]. The mol­ecule is built up from three fused six membered rings, one saturated and two unsaturated. The central unsaturated ring has a half-chair conformation, whereas the other unsaturated ring displays a chair conformation. The absolute configuration is deduced from the chemical pathway. The value of the Hooft parameter [−0.10 (6)] allowed this absolute configuration to be confirmed.

2-Isopropyl-4-methoxy-5-methylphenyl acetate

In the title compound, C13H18O3, the benzene ring is almost perpendicular to the acetoxy plane, making a dihedral angle of 89.33 (11)°. In the crystal, molecules are linked by weak C—H...O hydrogen bonds, forming a zigzag chain along thec-axis direction.