General procedure for the synthesis of 3-hydroxymethylpiperidine from ethyl (S)-3-piperidinecarboxylate: lithium aluminum hydride (LAH, 118 mL, 1.0 M in ether, 1.0 equiv.) was slowly added to a solution of tetrahydrofuran (THF, 250 mL) of the product of step A (18.5 g, 0.125 mmol) over a period of 20 min at 0 °C. The reaction mixture was gradually warmed to room temperature and subsequently heated to reflux for 2 hours. Upon completion of the reaction, it was cooled to room temperature and the reaction was quenched by slow addition of saturated sodium sulfate (Na2SO4) solution. The resulting slurry was dried by the addition of anhydrous sodium sulfate (Na2SO4), filtered through diatomaceous earth and concentrated to give a colorless oily product (13.7 g, 98% crude yield). The product was detected by chemical ionization mass spectrometry (CIMS) showing a molecular ion peak (MH+) of 116; the specific optical rotation ([α]20D) was -8.4° (determined by dissolving 5.0 mg of the sample in 2 mL of methanol).
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