(4R)-3-Hy-droxy-7-isopropyl-4-methyl-5,6-di-hydro-benzo-furan-2(4H)-one.

In the title compound, alternatively called α-hy-droxy-γ-alkyl-idenebutenolide, C12H16O3, two independent mol-ecules (A and B) crystallize in the asymmetric unit in each of which the 5,6-di-hydro-benzo ring has an envelope conformation. The torsion angle along the butadiene chain in the γ-alkyl-idenebutenolide core is -177.9 (2)° for mol-ecule A and 179.

(Z)-4-(2,5-Di-tert-butyl-anilino)pent-3-en-2-one.

In the crystal structure of the title ketoamine, C(19)H(29)NO, the bond lengths from the N atom through the alkene group to the ketone O atom show the presence of an extensively delocalized π-system. The dihedral angle between the plane of the phenyl ring and that of the alkene component is 63.45 (7)° due to steric hindrance exerted by the tert-butyl groups.

(E)-3-(1-Naphthyl-amino)-methyl-ene-(+)-camphor.

In the crystal structure of the title ketoamine {systematic name: (E)-1,7,7-trimethyl-3-[(1-naphthyl-amino)-methyl-idene]bicyclo-[2.2.1]heptan-2-one}, C(21)H(23)NO, there are two independent mol-ecules in the asymmetric unit.