Ethylene Oxide → 5-(2-Hydroxyethyl)furan-2(3H)-one

To a cooled solution of furan (3.40 g, 50.0 mmol) in THF (150 mL) was added n-BuLi (22 mL, 2.5M solution in hexane, 55.0 mmol) at 0° C. under inert gas atmosphere. The solution was allowed to warm to room temperature and stirred for 3 h. Then TMSCI (5.34 g, 50 mmol) was added dropwise at 0° C. and the solution was stirred for further 3 h at room temperature. Subsequently, the solution was again cooled to 0° C. and n-BuLi (22 mL, 2.5M solution in hexane, 55.0 mmol) was added a second time. After stirring for 3 h at room temperature ethyleneoxide (2.42 g, 55.0 mmol) was condensed by an acetone/dry ice condenser into the solution and the solution was stirred for further 12 h at room temperature. The mixture was quenched with aq NH4Cl, and then extracted with EtOAc and the combined organic layers were dried over Na2SO4 to afforded the desired product (5 g, 27.1 mmol, 54% over two steps) as a yellow liquid.