Methods for the synthesis of rhazinilam and its analogues

A review. Pyrrole contg. natural products were relatively rare. (R)-(-)-rhazinilam is an unusual monopyrrolic product isolated from nature but its formation is probably an artifact of the isolation procedure. The discovery and the identification of rhazinilam and analogs of rhazinilam were reviewed. The seven total syntheses of rhazinilam were described and critically evaluated some general conclusions concerning the use of protecting groups during the synthesis were presented. The comparison of the first synthesis with the more recent syntheses showed that the no. of steps needed starting from com. materials stayed almost const. despite the spectacular development of org. synthesis in recent years. Only one of the published syntheses gave a considerable improved overall yield. Most other syntheses give the natural product in comparable overall yield. [on SciFinder(R)]