Expeditious Access to Morphinans by Chemical Synthesis

Abstract Morphinans are essential medicines derived entirely from poppy supply chains rendered increasingly volatile by climate change. Here, we report a seven‐step, asymmetric chemical synthesis of (−)‐codeine from simple materials that requires a total combined reaction time of fewer than 24 hours. The efficiency of our approach arises from a double‐Heck cyclization reaction that generates two rings and two contiguous stereogenic carbon centres in the one pot. A subsequent photo‐redox hydroamination protocol provides a novel, atom‐economical means for assembling the piperidine D‐ring of codeine. Simple modifications to the closing stages of our sequence offer effective access to pharmacologically valuable derivatives of N ‐demethyl codeine. Our work highlights the capacity for contemporary, stand‐alone chemical synthesis regimes to diversify access to essential opiate medicines.