Synthesis of (S)-Ketamine via [1,3]-Chirality Transfer of a Stereocenter Created by Enantioselective Aldol Reaction

The stereocenter in the intermediate alcohol (86% ee), created by enantioselective oxazaborolidinone-promoted aldol reaction, was transferred to the stereocenter in the cyclohexanone ring, necessary for (S)-ketamine, via allyl cyanate-to-isocyanate rearrangement. The second asymmetric synthesis of (S)-ketamine has been achieved (87% ee).