Total Synthesis of Ellipticine Quinones, Olivacine, and Calothrixin B

A direct route to the synthesis of
biologically active ellipticine
quinones, olivacine, and calothrixin B is described. The prominent
key steps involved are Friedel–Crafts hydroxyalkylation followed
by oxidation and directed ortho-lithiation reactions
of readily available indole-2-carboxylate esters with appropriately
substituted pyridine and quinoline carboxaldehydes.