New chiral dendrimers with planar-chiral, cycloenantiomeric and topologically chiral cores were prepared in yields of up to 90% starting from a racemic 4-hydroxy[2.2]paracyclophane, a [2]rotaxane with sulfonamide groups in the wheel and axle positions and [2]catenane with a sulfonamide group in both of its macrocycles. The separation of the racemic mix-

No abstract

Known determinations of the absolute configuration of guaianolides were collected and found to be few. The absolute configurations of guaianolides rest on the assumption that 7-H always has alpha-orientation. For matricin, only the relative configuration was determined. On the basis of a detailed study of the NMR spectra of matricin and its epimers, and of synthetic, NMR, and CD studies with its decomposition product, chamazulene carboxylic acid, we were able to reconfirm the accepted 3S,3aR,4S,9R,9aS,9bS configuration of matricin.

The assignment of the absolute configuration of matricin rests on indirect evidence. On the basis of synthetic, NMR and CD studies with its decomposition product, chamazulene carboxylic acid, we were able to firmly establish the accepted 3S,3aR,4S,9R,9aS,9bS configuration of matricin.

The easily accessible [2.2]paracyclophane moiety should find its use in medicinal chemistry as it is a pharmacophoric substituent with the interesting feature of planar chirality.