Asymmetric Total Synthesis of Alstrostine G Utilizing a Catalytic Asymmetric Desymmetrization Strategy.

A highly effective enantioselective monobenzoylation of 1,3-diols has been developed for the synthesis of 1,1-disubstituted tetrahydro-β-carbolines. The chemistry has been successfully applied to the asymmetric total synthesis of (+)-alstrostine G, which also features a cascade Heck/hemiamination reaction enabling facile construction of the pivotal pentacyclic core.