Ethyl tetrahydro-2H-pyran-4-carboxylate (5.0 g, 34.7 mmol) was slowly added to a stirred suspension of lithium aluminum hydride (LiAlH4, 4.0 g, 104 mmol) in tetrahydrofuran (THF, 100 mL) at 0 °C. The reaction mixture was kept stirred at 0 °C for 1 hour. Subsequently, ethyl acetate (20 mL) was added slowly and dropwise to the reaction mixture to quench the excess LiAlH4, followed by the addition of 10% aqueous sodium hydroxide (NaOH). The resulting mixture was continued to be stirred for 30 minutes. Upon completion of the reaction, the reaction mixture was filtered through a diatomaceous earth pad to remove insoluble impurities. The filtrate was concentrated under reduced pressure to give the target product (tetrahydro-2H-pyran-4-yl) methanol (9) as a colorless oil. The yield was 3.9 g in 96% yield. The product was characterized by 1H NMR (400 MHz, DMSO-d5): δ 4.46 (broad single peak, 1H), 3.82 (double peak, J=8.0 Hz, 2H), 3.25-3.22 (multiple peaks, 4H), 1.62-1.52 (multiple peaks, 3H), 1.18-1.04 (multiple peaks, 1H).
