Synthesis
GENERAL METHOD: Tetrahydrothiopyran-4-one (40.10 g, 0.271 mol) was dissolved in methanol (700 mL), and sodium borohydride (15.36 g, 0.406 mol) was added in batches under ice-bath cooling, and the reaction was stirred for 1 hr. (NOTE: the reaction is exothermic and violent). Subsequently, the reaction mixture was continued to be stirred at 20°C for 2 hours. After completion of the reaction, the solvent was removed by concentration under reduced pressure to give a solid residue. To the residue was added a mixture of saturated aqueous sodium bicarbonate (150 mL) and ethyl acetate (250 mL) (Note: the product is soluble in water). After vigorous shaking, the organic layer was separated and the aqueous layer was further extracted with ethyl acetate (4 x 250 mL). All organic layers were combined, dried over anhydrous sodium sulfate and concentrated to dryness under reduced pressure to give the target product tetrahydro-2H-thiopyran-4-ol.
References
[1] Synthetic Communications, 2018, vol. 48, # 17, p. 2198 - 2205
[2] Chemistry - A European Journal, 2018, vol. 24, # 62, p. 16526 - 16531
[3] Bulletin of the Chemical Society of Japan, 1995, vol. 68, # 9, p. 2739 - 2750
[4] Chemical Communications (Cambridge, United Kingdom), 2002, # 10, p. 1070 - 1071
[5] Patent: EP3342765, 2018, A1. Location in patent: Paragraph 0337
