ent-(15S)-Pimar-8(14)-ene-15,16-diol

The title compound {systematic name: (S)-1-[(2S,4aR,8aR)-2,4b,8,8-tetra­methyl-2,3,4,4a,4b,5,6,7,8,8a,9,10-dodeca­hydro­phenanthren-2-yl]ethane-1,2-diol}, C₂₀H₃₄O₂, is an ent-pimarane diterpenoid which was isolated from the stem bark of Ceriops tagal. In the asymmetric unit, there are two crystallographically independent mol­ecules, which are conformationally almost identical. In each mol­ecule, the two cyclo­hexane rings of the fused three-ring system adopt chair conformations, while the cyclo­hexene ring is in an envelope conformation, with the methylene C atom next to the side chain as the flap atom. In the crystal, mol­ecules are stacked in columns along the b axis through O—H...O hydrogen bonds.

2-(2,4,5-Trimeth­oxy­phen­yl)-2,3-dihydro­quinolin-4(1H)-one

In the title aza-flavanone, C₁₈H₁₉NO₄, an intra­molecular cyclization product of chalcone, the central heterocyclic ring is in an envelope conformation and the dihedral angle between the benzene rings is 51.03 (10)°. The meth­oxy groups at the ortho and para positions are slightly twisted from the benzene ring to which they are bound [C—O—C—C = 21.9 (3) and −171.93 (18)°, respectively], whereas the meth­oxy group at the meta position is almost coplanar [C—O—C—C = 3.5 (3)°]. In the crystal, mol­ecules are linked by N—H...O hydrogen bonds and weak C—H...O inter­actions into chains along the [001] direction. Weak C—H...π inter­actions also occur.