aza-Prins-pinacol approach to 7-azabicyclo[2.2.1]heptanes and ring expansion to [3.2.1]tropanes.
[reaction: see text] 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.
Armstrong
Alan
A
Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, UK. a.armstrong@imperial.ac.uk
Shanahan
Stephen E
SE
D001372:Aza Compounds / Q000138:chemical synthesis / Q000737:chemistry; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D006536:Heptanes / Q000138:chemical synthesis*; D015394:Molecular Structure; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry; D011759:Pyrrolidines / Q000737:chemistry; D014326:Tropanes / Q000138:chemical synthesis*
D001372:Aza Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D006536:Heptanes; D009842:Oligopeptides; D011759:Pyrrolidines; D014326:Tropanes; C414027:aza-pinacol