The first isolation of unsubstituted porphyrinogen and unsubstituted 21-oxaporphyrinogen by the '3+ 1'approach from 2, 5-bis (hydroxymethyl) pyrrole and tripyrrane …
The treatment of 2, 5-bis (hydroxymethyl) pyrrole or 2, 5-bis (hydroxymethyl) furan with pyrrole in the presence of hydrochloric acid gave tripyrrane and 2, 5-bis (2-pyrrolylmethyl) furan in 58–61% yield, which afforded the simplest porphyrinogen (hexahydroporphine) and 21-oxaporphyrinogen by the '3+ 1'approach in 14 and 11% yields, respectively. 21- Oxaporphyrinogen has been shown to adopt a 1, 2-alternated conformation in the solid ...
