Total Synthesis of (–)-Flueggeacosine C

Herein\nwe describe a total synthesis of the heterodimeric securinega\nalkaloid (−)-flueggeacosine C (<b>8</b>). The convergent\nsynthetic strategy is based on a Liebeskind–Srogl cross-coupling\nreaction that combines a benzoquinolizidine fragment with a securinine-type\nalkaloid. An acyloxy nitroso ring-expansion was employed as the key\nstep in accessing benzoquinolizidine <b>9</b>, and a novel intramolecular\nDiels–Alder reaction of an allenic acid-containing pyridone\nexpeditiously delivers the skeleton of the securinine-type fragment\n(<b>16</b>). Finally, a Cu-catalyzed hydroboration-oxidation\nsequence was employed to regio- and diastereoselectively introduce\nthe secondary alcohol found in <b>8</b>.