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To a slurry of 7.3 g (26.14 mmol) of the tartrate salt of (S)-pipecolic acid (Egbertson M. and S. J. Danishefsky, J. Org. Chem. 54:11 (1989) in 75 mL of dry benzene was added 13.5 mL (0.13 mol) of benzyl alcohol and 5.48 g (28.8 mmol) of p-toluenesulfonic acid monohydrate. The reaction mixture was heated at reflux under a Dean-Stark trap for 2 h and then cooled to room temperature. The solution was then diluted with 400 mL of ether and stirred overnight at 4° C. The resulting white solid was collected on a filter, washed with hexane and dried in vacuo to give 9.2 g (90%) of the p-toluenesulfonic acid salt of benzyl pipecolate (134). 1H NMR (300 MHz, D2O) δ7.63 (d), 7.41 (s), 7.28 (d), 5.26 (ABq), 4.8 (s), 4.03 (dd), 3.92 (dd), 3.51-3.39 (m), 3.15-2.93 (s), 2.40 (s), 2.36-2.24 (m), 1.98-1.53 (m).

1. temperatureThe reaction mixture was heated
2. temperatureat reflux under a Dean-Stark trap for 2 h
3. customThe resulting white solid was collected on a filter
4. washwashed with hexane
5. customdried in vacuo