Total Synthesis of Neodysiherbaine A via 1,3-Dipolar Cycloaddition of a Chiral Nitrone Template.

The total synthesis of neodysiherbaine A was achieved via 1,3-dipolar cycloaddition of a chiral nitrone template with a sugar-derived allyl alcohol in the presence of MgBr2·OEt2. This cycloaddition constructed the C2 and C4 asymmetric centers in a single step. Then reductive cleavage, intramolecular SN2 reaction of the tertiary alcohol, and oxidation of the primary alcohol afforded neodysiherbaine A.