Hexahalogenated bipyrroles

The pyrrole ring is widely distributed in nature. It occurs in both terrestrial and marine plants and animals [1-3]. Examples of simple pyrroles include the Pseudomonas metabolite pyrrolnitrin, a recently discovered seabird hexahalogenated bipyrrole [4], and an ant trail pheromone. An illustration of the abundant complex natural pyrroles is konbu acidin A, a sponge metabolite that inhibits cyclin-dependent kinase 4. The enormous reactivity of pyrrole in electrophilic substitution reactions explains the occurrence of more than 100 naturally occurring halogenated pyrroles [2, 3]. 

Although V-protected 2-lithiopyrroles are readily generated and many types are known [6, 26], these intermediates have not generally been employed to synthesize halogenated pyrroles. One exception is the synthesis of the two natural seabird hexahalogenated bipyrroles 15 and 17,... 

The following four hexahalogenated l,l -dimethyl-2,2 -bipyrroles, 178-181, have been detected in marine mammal blubber (02MI244). 

---