Methyl 2-(8a-hy­droxy-4a-methyl-8-methyl­enedeca­hydro­naphthalen-2-yl)acrylate

The title compound, C16H24O3, was synthesized from ilicic acid which was isolated from the aerial part of Inula Viscosa­ (L) Aiton [or Dittrichia Viscosa­ (L) Greuter]. The mol­ecule contains two fused six-membered rings both in chair conformations. In the crystal, mol­ecules are linked into chains running parallel to the a axis by O—H⋯O hydrogen bonds

3-[4-(Dimethyl­amino)­phen­yl]-1-(4a,8-dimethyl-1,2,3,4,4a,5,6,8a-octa­hydro­naphthalen-2-yl)prop-2-en-1-one

The title compound, C23H31NO, was semisynthesized from isocostic acid, isolated from the aerial part of Inula Viscosa­ (L) Aiton [or Dittrichia Viscosa­ (L) Greuter]. The cyclo­hexene ring has a half-chair conformation, whereas the cyclo­hexane ring displays a chair conformation. The dihedral angle between the latter ring and its substituent is 83.6 (7)°

1-(4a,8-Dimethyl-1,2,3,4,4a,5,6,8a-octa­hydro­naphthalen-2-yl)-3-phenyl­prop-2-en-1-one

The title compound, C21H26O, was semisynthesized from isocostic acid, isolated from the aerial part of Inula Viscosa­ (L) Aiton [or Dittrichia Viscosa­ (L) Greuter]. The cyclo­hexene ring has a half-chair conformation, whereas the cyclo­hexane ring displays a chair conformation

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

1-(4a,8-Dimethyl-1,2,3,4,4a,5,6,8a-octa­hydro­naphthalen-2-yl)-3-(4-methyl­phen­yl)prop-2-en-1-one

The title compound, C22H28O, was isolated from the aerial part of Inula viscosa­ (L) Aiton [or Dittrichia viscosa­ (L) Greuter]. The cyclo­hexene ring has a half-chair conformation, whereas the cyclo­hexane ring displays a chair conformation being substituted at position 2 by a 3-(4-methyl­phen­yl)prop-2-enoyl group. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds link mol­ecules into chains in the [010] direction

1-[(2R,4aR,8R,8aR)-8-Hy­droxy-4a,8-di­methyl­perhydronaphthalen-2-yl]ethan-1-one

The title compound, C14H24O2, was synthesized from ilicic acid, which was isolated from the aerial part of Inula Viscosa­ (L) Aiton [or Dittrichia Viscosa­ (L) Greuter]. The mol­ecule contains two fused six-membered rings, which both display a chair conformation. In the crystal, mol­ecules are linked into chains propagating along the b axis by inter­molecular O—H⋯O hydrogen bonds