Synthetic studies on the perhydropyrrolo[2,1-j]quinoline marine alkaloids lepadiformine and cyclindricine C using a 2-azapentadienyl anion cycloaddition. Synthesis of 2,13-diepilepadiformine (or 2-epi-11-deoxycylindricine C)

Article abstract of DOI:10.1016/S0040-4039(97)00632-1

Tin-lithium exchange of 13 with n-BuLi produced the 2-azapentadienyl anion 6 (R = CH₃), which participated in a [π4s+π2s] cycloaddition reaction with phenyl vinyl sulfide to afford the spirocyclic pyrrolidine 14, which as coverted to 2,13-diepi