Play It Again, Strychnine

A German group's new synthesis for strychnine is now the shortest route to a benchmark target for synthetic organic chemists.

Christine Beemelmanns and Hans-Ulrich Reissig in the chemistry department at the Free University in Berlin report an 11-step racemic synthesis of strychnine that features a single-step creation of two rings and three stereogenic centers from simple linear indole precursors using a samarium diiodide-induced cascade reaction (Angew. Chem. Intl. Ed., DOI: 10.1002/anie.201003320).

"This key step is super surprising," comments Phil Baran, a synthetic organic chemist at Scripps Research Institute in San Diego. "With this reaction, they take a straight chain compound with little complexity and turn it in to a highly complex molecule."

Strychnine itself has no commercial value, but Reissig says he hopes several steps in the synthesis could be useful in other synthetic schemes. "Strychnine is the mountain many synthetic chemists climb," Baran adds. "The point is not so much getting to the top, but the route they take."