The preferred steric course of quaternisation of 1-alkylpiperidines

摘要: Previous methods of assignment configuration to pairs diastereoisomeric quaternary salts type +NR1R2X–, +NR2R1X– derived from N-alkylpiperidines are re-examined and their general utility confirmed. Our previous conclusion, that axial attack is preferred in most reactions marked stereoselectivity, extended cover a preference boat-axial (formally, equatorial) certain 3-azabicyclo[3,3,1]nonanes. The ambiguous position regarding quaternisations N-alkylnor-tropanes, -tropines, -pseudotropines discussed. Other workers' results, arguments, conclusions examined