Synthesis of (+)-solenopsin via Pd-catalyzed N-alkylation and cyclization

Synthesis of (+)-solenopsin, a 2,6-disubstituted piperidine alkaloid, isolated from fire ants (Solenopsis), was achieved. Stereoselective construction of trans-2,6-piperidine ring moiety was performed using palladium-catalyzed cyclization. Chain elongation using Grubbs 2nd catalyst followed by the reduction of double bond and the deprotection of the Cbz group afforded (+)-solenopsin.