Ozone → 5-(2-hydroxyethyl)-2-benzofuran-1(3H)-one

Participants

Reaction Steps

To a solution of 5-(prop-2-en-1-yl)-2-benzofuran-1(3H)-one (13.5 g, 45.2 mmol) in 200 mL DCM/MeOH (V/V=1:1) was bubbled O3 at −78° C. for 30 min, and N2 was bubbled for another 15 min at −78° C. Then 20 mL of Me2S were added, and the mixture was stirred at r.t. overnight before concentrating to dryness. The residue was dissolved in MeOH (100 mL) and then cooled to 0° C. NaBH4 (5.90 g, 155 mmol) was added in portions. The resulting mixture was stirred at 0° C. for 1 hr, then quenched with citric acid (aq.) and extracted with EtOAc (3×500 mL). The combined organic layers were washed with NaHCO3 (aq.) and brine, dried over anhydrous Na2SO4 and concentrated to dryness. The residue was purified via silica column chromatography (EtOAc/Petrol Ether=1:5) to give 5-(2-hydroxyethyl)-2-benzofuran-1(3H)-one.

Provenance & Evidence