The practicable synthesis of all imaginable isomeric heterocyclic moieties 8-11 and ent-8-ent-11 of the naphthylisoquinoline alkaloids is described. The stereoinformation at C-3 is induced by asymmetric reductive amination, using 1-phenylethylamines of either enantiomeric series as chiral auxiliaries. The key step of the stereocontrolled construction of the stereocenter at C-1 is the diastereoselective reduction of the corresponding dihydroisoquinolines, as obtained by Bischler-Napieralski synthesis, or the regio-and stereoselective Pictet-Spengler reaction of arylisopropylamines with acetaldehyde, respectively.

Biaryl Com pounds, Exciton Chirality M ethod, C N D O /S , Boltzmann W eighting, CD The circular dichroism (CD) o f the biaryls ancistrocladeine and dioncophylleine A has been studied. The C N D O /S method in combination with a Boltzmann weighting o f different struc tures using AM 1 energies has been applied to reproduce the experimental CD spectra o f the two alkaloids with known absolute configuration at with those o f the exciton chirality method.

Polystyrene sulfonate (PSS) of different molecular weight M(w) is adsorbed to oppositely charged DODAB monolayers from dilute solutions (0.01 mmol/L). PSS adsorbs flatly in a lamellar manner, as is shown by X-ray reflectivity and grazing incidence diffraction (exception: PSS with M(w) below 7 kDa adsorbs flatly disordered to the liquid expanded phase). The surface coverage and the separation of the PSS chains are independent of PSS M(w). On monolayer compression, the surface charge density increases by a factor of 2, and the separation of the PSS chains decreases by the same factor. Isotherms show that on increase of PSS M(w) the transition pressure of the LE/LC (liquid expanded/liquid condensed) phase transition decreases. When the contour length exceeds the persistence length (21 nm), the transition pressure is low and constant. For low-M(w) PSS (<7 kDa) the LE/LC transition of the lipids and the disordered/ordered transition of adsorbed PSS occur simultaneously, leading to a maximum in the contour length dependence of the transition enthalpy. These findings show that lipid monolayers at the air/water interface are a suitable model substrate with adjustable surface charge density to study the equilibrium conformation of adsorbed polyelectrolytes as well as their interactions with a model membrane.

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