Efficient synthesis of the κ-opioid receptor agonist CJ-15,161:: four stereospecific inversions at a single aziridinium stereogenic center

An efficient four-step sequence has been developed for the synthesis of the kappa-opioid receptor agonist CJ-15,161. The process features four consecutive regioselective and stereospecific inversions at a single aziridinium stereogenic center, which leads to overall retention of stereochemistry, in a single operation. The chemistry is straightforward, practical and amenable to large-scale synthesis. (C) 2003 Elsevier Ltd. All rights reserved.