Alkynylation of Thiolactams. New Synthesis of α-Substituted Pyrrolidine and Piperidine Alkaloids
Alkynylation of S-alkylthioamidium salts of thiolactams with lithium acetylides followed by reduction with LiAlH4 provided α-alkynylazacycloalkanes, which on reduction, or hydroboration followed by oxidation, gave α-substituted pyrrolidine and piperidine alkaloids.