A round bottom flask with stirrer was loaded with NaH (0.741 mL, 13.334 mmol, 3.334 eq), sealed with septum and purged with N2, followed by the addition of THF (30.0 mL) and substrate (0.414 mL, 4.000 mmol, 1.000 eq). After 1 h reaction, EtI (1.560 g, 10.000 mmol, 2.500 eq) was added dropwise to the reaction mixture and let to react overnight. The reaction mixture was quenched by the addition of EtOH and then water. The solution was extracted with EtOAc (3x20 mL), dried over MgSO4 and concentrated via distillation to give the desired product.