FromCorydalisincisa (+)-corynoline (2) was isolated together with (±)-corynoline (2'), which has been reported to be the major alkaloid. Optical resolution of 2' was achieved by resolving the corresponding diastereomeric esters with (-)-menthoxyacetic acid. The quaternary hydroxide of (+)-corynoline-O-acetate (3) was subjected to Emde degradation to afford the hydromethine base (5), the methiodide
employed in an enantioselective palladium‐catalyzed α‐arylation with the chiral monophosphorus ligand BI‐DIME. This process enabled an efficient synthesis of the antidepressant (S)‐nafenodone, a four‐step enantioselectivesynthesis of the Sceletium alkaloid (+)‐sceletium A‐4, a concise five‐step enantioselectivesynthesis of (−)‐corynoline, as well as a three‐step preparation of (−)‐DeN‐corynoline