Concise formal syntheses of the dendrobate alkaloid (+)-241D
and its C-4 epimer are described by means of a highly diastereoselective
Barbier-type indium-mediated allylation strategy involving an (S)-(N-tert-butanesulfinyl)imine.
(N-tert-butanesulfinyl)imine - piperidine alkaloids - aldol reaction - alkaloid-241D - allylation