The proposed intermediacy of the spiro-pyrrolenine for the biosynthesis of uroporphyrinogen III has focussed attention on its synthesis. Several different approaches to close analogues of this compound are explored, including (a) the synthesis of a dilactone bridged dipyrrolic pyrrolenine, (b) deactivation of two of the pyrrole rings of the macrocycle by attaching 3-methoxycarbonyl groups and (c) approaches to spiro-macrocyclic compounds via dipyrroketones. The chemistry of the different types of synthetic intermediates is described.
Department of Chemistry
University of Cambridge