A concise route toward (−)-strychnine is presented. Key steps include the photoredox-catalytic C2-cyanomethylation of Boc-l-Trp-OMe and a condensation-electrocyclization cascade linking two fragments convergently to obtain an advanced intermediate. A photochemical decarboxylation provided convenient access to strychnofluorine, which could be transformed through the Wieland–Gumlich aldehyde to strychnine. All building blocks can be traced back to renewable sources.
Wiechert et al. (Sun,) studied this question.