Bipyrroles. Part IV. Some Further Reactions
David Dolphin, Grigg, R., Johnson, A.W., and Leng, J.
J. Chem. Soc.
Uv irradiation of CHCl3 solutions of certain 2,2'-bipyrroles has given dichlorocarbene adducts. The new CHCl2 group is shown to occupy the 5-and not the 2-position in all the cases examined. Alkaline hydrolysis converts the adducts into 5-formyl-2,2'-bipyrroles, which have been condensed with α-free 2,2'-bipyrroles to yield the 5,5'-di(pyrrol-2-yl)dipyrromethenes (I). Other new tetrapyrrolic systems based on 2,2'-bipyrrole which have been synthesized are the 1',8’;-dideoxy-b-norbilenes-a (II) and the 1',8'-dideoxy-a-norbilenes-b (III).