Computationally Guided Organometallic Chemistry:  Preparation of the Heptacyclic Pyrazine Core of Ritterazine N

2006-03-31T00:00:00Z (GMT) by Douglass F. Taber Karen V. Taluskie
Diels−Alder cycloaddition of <b>10</b> followed by Wittig homologation and intramolecular diene cyclozirconation of the resulting triene under equilibrating conditions led to the tricyclic 6−6−5 ketone <b>5</b> with high diastereocontrol. The derived α-azido ketone <b>16</b> cyclized efficiently to the heptacyclic pyrazine core of ritterazine N.