The natural product (-)-pironetin is a structurally simple small molecule microtubule-perturbing agent whose biological activities appear to be exquisitely dependent on defined stereochemistry and the presence of an eletrophilic alpha,beta-unsaturated lactone moiety. We used alkaloid-catalyzed acyl halide-aldehyde cyclocondensation reactions in asymmetric total syntheses of (-)-pironetin and th...