PHOTOCHEMICAL-SYNTHESIS OF MEDIUM-RING AZALACTAMS FROM N-(AMINOALKYL)-2-STILBENECARBOXAMIDES

The photochemical reactions of several N-(aminoalkyl)-2-stilbenecarbox amides have been investigated. The amine groups quench the stilbenecar boxamide fluorescence intensity, presumably via intramolecular electro n transfer. The relatively low quenching efficiencies and the absence of intramolecular exciplex formation are attributed to the molecular s tructure which prevents effective overlap between the stilbene and ami ne chromophores. The secondary amines are observed to undergo regiosel ective intramolecular addition to afford 9- or 10-ring azalactams in 2 5-43% isolated yield. The dependence of both fluorescence quenching an d adduct formation upon molecular structure are discussed. (C) 1998 El sevier Science S.A.