aza-Prins-pinacol Approach to 7-Azabicyclo[2.2.1]heptanes and Ring Expansion to [3.2.1]Tropanes
journal contributionposted on 31.03.2005, 00:00 by Alan Armstrong, Stephen E. Shanahan
The 7-azabicyclo[2.2.1]heptane ring system can be rapidly accessed from 5-(1-hydroxyallyl)-2-alkoxy-N-tosylpyrrolidines via an unusual aza-Prins-pinacol reaction mediated by Lewis acid. The products can undergo ring expansion to isomeric tropanones. These reactions show promise for a concise entry to biologically relevant azabicyclic targets.