SYNTHESIS AND STRUCTURE OF MACROCYCLIC DIOXALACTAMS, DITHIALACTAMS, DIAZATETRALACTAMS AND DERIVATIVES

The high yield stepwise synthesis of 18-membered dioxa-, dithia- and d iazatetralactams is described. The two key steps are: i) the dissymetr ization of the reactivity of a diacid via its cyclic anhydride and ii) the activation-cyclization of the intermediate diamide diacid avoidin g the high-dilution technique. Two series of diazatetralactam derivati ves are prepared: bibranched compounds bearing various substituents an d macrobicyclic or macrotricyclic species with phenantroline units. Th e main conformer of the dioxaretralactam was found by C-13 nmr and mol ecular modelling to have a D-2 symmetry while the dithiatetralactam in vacuo and the Boc substituted diazatetralactam in the solid state hav e a C-2 symmetry. Copyright (C) 1996 Elsevier Science Ltd.