10.1021/jo052656m.s001 Douglass F. Taber Douglass F. Taber Karen V. Taluskie Karen V. Taluskie Computationally Guided Organometallic Chemistry:  Preparation of the Heptacyclic Pyrazine Core of Ritterazine N American Chemical Society 2006 Ritterazine tricyclic Computationally cyclized heptacyclic pyrazine core Organometallic cycloaddition azido Heptacyclic Pyrazine Core diastereocontrol Diel triene equilibrating conditions Preparation ritterazine N Wittig homologation Guided intramolecular diene cyclozirconation ketone 2006-03-31 00:00:00 Dataset https://acs.figshare.com/articles/dataset/Computationally_Guided_Organometallic_Chemistry_Preparation_of_the_Heptacyclic_Pyrazine_Core_of_Ritterazine_N/3230191 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.