Synthesis
General procedure for the synthesis of 2H-pyran-3(6H)-ones from 3,6-dihydro-2H-pyran-3-ol: 3,6-dihydro-2H-pyran-3-ol (2.44 g, 24.37 mmol) was dissolved in dichloromethane (100 mL) and the solution was cooled to 0 °C. Subsequently, Dess-Martin periodinane (10.34 g, 24.37 mmol) was slowly added. The reaction mixture was slowly warmed to room temperature over a period of 5 hours. After completion of the reaction, the reaction mixture was filtered through diatomaceous earth. After concentration of the filtrate, the crude product was purified using a 100 g SNAP Biotage column (eluent: 0-80% hexane solution of ethyl acetate) to afford 2H-pyran-3(6H)-one (2.33 g, 23.75 mmol, 97% yield) as a colorless oil.1H NMR (400 MHz, CDCl3) δ ppm: 7.07- 7.17 (m, 1H), 6.15-6.25 (m, 1H), 4.39 (t, J = 2.54 Hz, 2H), 4.19 (s, 2H).
References
[1] Patent: WO2012/145569, 2012, A1. Location in patent: Page/Page column 79; 80
[2] Angewandte Chemie - International Edition, 2005, vol. 44, # 33, p. 5306 - 5310
[3] Synlett, 2006, # 4, p. 621 - 623
[4] Patent: WO2014/134566, 2014, A2. Location in patent: Paragraph 0547
