To a stirred suspension of a 60% sodium hydride (NaH) dispersion in mineral oil (2.30 g, 57.69 mmol), an anhydrous N,N-dimethylformamide (DMF, 150 mL) solution of 1,5-pentanediol (5.0 g, 48.07 mmol) was slowly added dropwise at 0°C over 15 minutes. After dropwise addition, the reaction mixture was stirred at room temperature for 1 hour. Subsequently, benzyl bromide (5.75 mL, 48.07 mmol) was slowly added over 15 minutes and stirring was continued at the same temperature for 2 hours. After completion of the reaction, the reaction mixture was quenched with ice-cold water. The crude product was extracted with ethyl acetate (2 x 30 mL), the organic layers were combined, washed with saturated brine (3 times), dried over anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure. The residue was purified by silica gel column chromatography with petroleum ether-ethyl acetate (7:3, v/v) as eluent to obtain the target product 5-benzyloxy-1-pentanol. Yield: 89% (7.87 g) as a colorless oily liquid. IR spectrum (CHCl3, cm-1): υmax 700, 714, 1028, 1072, 1116, 1177, 1278, 1316, 1388, 1453, 2865, 2938, 3064, 3332; 1H NMR (200 MHz, CDCl3): δ 1.47-1.70 (m, 6H), 3.47 (t, J = 6.3 Hz, 2H), 3.62 (t, J = 6.1 Hz, 2H), 4.49 (s, 2H), 7.31 (s, 5H); 13C NMR (50 MHz, CDCl3): δ 22.3, 29.3, 32.3, 62.2, 70.2, 72.8, 127.5, 128.2, 138.3; High-resolution Mass Spectrometry (ESI): calculated value [C12H18O2 + H]+ (M + H) 195.1385, measured value 195.1390.
