Model studies on the type-III porphyrin rearrangement: synthesis and chemistry of pyrrolylmethylpyrrolenines and related systems

Abstract

Synthetic routes to 2,2-disubstituted pyrrolenines are developed and used to construct a pyrrolylmethyl-pyrrolenine (24) of the type postulated to be an intermediate in the rearrangement which generates the natural type-III porphyrins; the synthetic system is found to undergo ready proton-catalysed rearrangement which models the proposed biosynthetic process and thus shows its feasibility.