A Stereocontrolled Alkylation of Chiral Pyridinium Salts with Grignard Reagents: Synthesis of (+)-Normetazocine and (+)-Nordextrorphan

Article abstract of DOI:10.1021/jo00060a019

The synthesis of chiral pyridinium salts 3, bearing lipophilic counteranions, is described.These salts, soluble in THF or toluene, undergo nucleophilic alkylation with benzylic Grignard reagents to give, after reduction of the unstable dihydropyridine int