α-Costic anhydride

The title compound [systematic name: 2-(4a,8-dimethyl-1,2,3,4,4a,5,6,8a-octa­hydro­naphthalen-2-yl)acrylic acid anhydride], C30H42O3, is a new isocostic anhydride which was synthesized from the aerial part of Inula Viscosa­ (L) Aiton [or Dittrichia Viscosa­ (L) Greuter]. The mol­ecule adopts an essentially linear shape with two terminal fused-rings bridged by the anhydride group. The external rings have the same conformation (half-chair) while each of the two inner rings has an almost ideal chair conformation. In the crystal, inter­molecular C—H⋯O inter­actions link the mol­ecules into a two-dimensional array in the bc plane

N-[4-Acetyl-5-methyl-5-(2-p-tolyl­prop­yl)-4,5-dihydro-1,3,4-thia­diazol-2-yl]acetamide

The title heterocyclic compound, C17H23N3O2S, was synthesized from 4-(4-methyl­cyclo­hex-3-en­yl)pent-3-en-2-one, which was isolated from Cedrus atlantica essential oil. The thia­diazole ring adopts a flattened envelope conformation, with the flap sp 3-hybridized C atom lying 0.259 (1) Å out of the plane of the other four atoms. The screw-related mol­ecules are linked into chains along the b axis by inter­molecular N—H⋯O hydrogen bonds