Diethyl Ether → (S)-2-(Piperidin-2-yl)ethanol

Participants

Reaction Steps

Thus, a mixture of R and S enantiomers of piperidine-2-ethanol obtained from Acros and used as received (127 g, 980 mmol) was dissolved in 95% EtOH (260 mL). To the aliphatic alcohol solution was added to (S)-(+)-camphorsulfonic acid obtained from Acros (228.7 g, 1.0 eq.) in 95% EtOH (150 mL) and the resulting solution was warmed to reflux. To the warm solution was added Et2O (600 mL) and the solution cooled to room temperature and let stand 3 days. The resulting crystals were filtered and dried in vacuo (25 g): and analyzed by mp 173° C. (lit. 168° C.). The salt was then dissolved in NaOH (3M, 100 mL) and stirred 2 hours and the resulting solution was extracted with CH2Cl2 (5×100 mL). The combined organics were dried over Na2SO4, filtered and concentrated under reduced pressure to give (S)-piperidine-2-ethanol (7.8 g) a portion of which was recrystallized from Et2O: mp=69-70° C. (lit. 68-69° C.); [α]D=14.09° (CHCl3, c=0.2). Overall yield of S-isomer isolated, based on initial weight of starting alcohol was 6.1%.

Provenance & Evidence