403802-41-5

203664-61-3

403802-41-5

General procedure for the synthesis of tert-butyl 4-(3-hydroxyprop-1-yn-1-yl)piperidine-1-carboxylate from tert-butyl 4-(2,2-dibromoethenyl)piperidine-1-carboxylate: 6.0 g (16.3 mmol) of tert-butyl 4-(2,2-dibromoethenyl)piperidine-1-carboxylate was dissolved in 150 ml of THF at -78 °C and 21.4 ml ( 34.2 mmol) n-butyllithium (~1.6 M hexane solution) was added slowly. After keeping the reaction at this temperature for 2 hours, 4.9 g (16.3 mmol) of paraformaldehyde was added. The reaction mixture was then slowly warmed to room temperature and the reaction continued for 3 hours. Upon completion of the reaction, the mixture was partitioned (3 times) between water and ether. The organic phase was washed with 10% NaCl aqueous solution, dried over anhydrous Na2SO4 and then concentrated. Purification by rapid chromatography on silica gel (hexane/EtOAc 4:1) afforded 3.34 g (86% yield) of the target product, tert-butyl 4-(3-hydroxyprop-1-yn-1-yl)piperidine-1-carboxylate, with mass spectrometry (MS) revealing the molecular ion peak at 239 (M).