Total Synthesis Highlights

ing system of vindoline, appropriately oxygenated, was assembled! The precursor 7 was flat, so it
offered no opportunity for chiral synthesis. Fortunately, 10 and ent-10 proved to be very easy to
resolve by chiral chromatography.
To complete the synthesis, the δ-lactam 11 was oxygenated to 12. Conditions for desulfurization
of the derived thiolactam also effected debenzylation, to give, after acetylation, the ether 13.
Pt-mediated hydrogenolysis gave 14, which was dehydrated to vindoline (1).
A complementary synthetic route, based on the E isomer of 6, and so leading through the ether 15,
is also described. Although slightly longer, this approach was about as efficient as the route via
11.