Assembly of the gephyrotoxin ring system via a [4+1] approach to 3-pyrrolines

Article abstract of DOI:10.1016/S0040-4039(00)70644-7

Heating azidodienes 19 at 70°C produced the tricyclic 3-pyrrolines 20 and 21 in one operation. The diastereoselectivity of this process was examined, and found to be controlled by the conformation of the cyclization precursor. Compound 20d incorporates the basic features of gephyrotoxin 3.