SYNTHESIS OF cis AND trans-2,6-DIALKYLATED PIPERIDINES THROUGH HIGHLY REGIOSELECTIVE Α-ALKYNYLATION OF PYRIDINIUM SALTS AND ITS APPLICATION TO SYNTHESIS OF (+)-SOLENOPSINE A

Article abstract of DOI:10.1246/cl.1984.1129

Reactions of N-methoxycarbonyl-2-alkylpyridinium salts with alkynyl Grignard reagents give exclusively 2,6-disubstituted 1,2-dihydropyridines, from which cis- and trans-2,6-dialkylated piperidines can be derived selectively.Consequently, (+)-solenopsine A is efficiently synthesized by this sequence.