(+/-)-Aspidospermidine (1) has been synthesized from readily available meth
yl 3-ethyl-2-oxocylopentanecarboxylate (17) in 5.9% yield over 13 steps. Th
e key step of the synthesis is an intramolecular cascade reaction that simu
ltaneously forms the B, C, and D rings of 1. A high-yielding method of clos
ing the remaining E ring is also described.