Preparation of enantiopure 1-azabicyclo[3.2.2]nonanes functionalized at carbon C3, from cinchonine and cinchonidine. stereoselective solvolysis and an easily enolizable ketone.
Solvolysis of C9 mesylated cinchonidine 1-OMs and cinchonine 2-OMs in solvent MeOH, EtOH, and CF(3)CH(2)OH affords ring-expanded 1-azabicyclo[3.2.2]nonanes oxygenated at carbon C3 ("second Cinchona rearrangement"). The newly introduced substituents at C3 and the neighboring quinolyl group Q' at C2 adopt quasiequatorial positions. The derived 1-azabicyclo[3.2.2]nonan-3-ones 5 and 6 are easily equilibrated. On contact with MeOD uptake of deuterium takes place at room temperature.
Röper
Stefanie
S
Department of Organic Chemistry, University of Hannover, Schneiderberg 1B, D-30167 Hannover, Germany.
Franz
M Heiko
MH
Wartchow
Rudolf
R
Hoffmann
H Martin R
HM
D000473:Alkanes / Q000138:chemical synthesis*; D001372:Aza Compounds / Q000138:chemical synthesis*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis*; D002930:Cinchona Alkaloids / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013696:Temperature
D000473:Alkanes; D001372:Aza Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D002930:Cinchona Alkaloids; D007659:Ketones; C041622:cinchonidine; C017573:nonane; C010086:cinchonine