Barton Zard Synthesis
The Barton-Zard Synthesis method of pyrrole synthesis is a cyclisation reaction between a nitroalkene and α-isocyanoacetate under base conditions.[1]
Mechanism
It consists in three main steps:
- Michael-type addition between the α-isocyanide carbonyl enolate and the nitroalkene.
- Cyclization between isocyanide's carbene and the anion formed in the α position of nitro group.
- Elimination of nitro group with consecuent aromatization.[2]
References
- ^ J. Jack Li, Heterocyclic Chemistry, 2005, 1, 70.
- ^ Jie Jack Li (2009). Name Reactions. A Collection of Detailed Reaction Mechanisms 4th Edition. Berlin, De: Springer. ISBN 978-3-642-01052-1.