The denudatine-type diterpenoid alkaloids cochlearenine, N-ethyl-1 alpha-hydroxy-17-veratroyldictyzine, and paniculamine have been synthesized for the first time (25, 26, and 26 steps from 16, respectively). These syntheses take advantage of a common intermediate (8) that we have previously employed in preparing aconitinetype natural products. The syntheses reported herein complete the realization of a unified strategy for the preparation of C-20, C-19, and C-18 diterpenoid alkaloids.