SYNTHETIC STUDIES RELEVANT TO BIOSYNTHETIC RESEARCH ON VITAMIN-B12 .10. CONSTRUCTION OF THE EAST AND WEST BUILDING-BLOCKS FOR SYNTHESIS OF ISOBACTERIOCHLORINS

Studies with model compounds have led to the development of effective methods for (a) linking the pyrrolic rings to the reduced rings present in the isobacteriochlorin system (e.g. 4) and (b) for introducing the carbon at C-5 required to complete the macrocycle. In the course of this work, many new pyrrolic systems have been prepared and characterised.