Compound 9: A 5 mL microwave vial was charged with a stir bar and chlorosulfonyl isocyanate (ClSO2NCO) (0.18 mL, 0.30 g, 2.14 mmol, 2.5 equiv.) and cooled to 0 °C using an ice-water bath. Formic acid (0.08 mL, 0.098 g, 2.15 mmol, 2.5 equiv.) was slowly added (Caution! Vigorous gas evolution during addition), and the mixture was stirred for 10 minutes, during which a white solid formed. Anhydrous acetonitrile (4 mL) was added to this solid. The resulting solution was stirred at room temperature for 12 h. After 12 h, the reaction mixture was cooled to 0 °C using an ice-water bath, and alcohol 8 (0.28 g, 0.854 mmol, 1 equiv.) dissolved in 0.6 mL of DMA was added dropwise using a syringe. The resulting solution was warmed to room temperature over 5 h. Subsequently, the reaction was quenched with ice water (10 mL) and transferred to a separatory funnel. The organic layer was separated, and then the aqueous layer was extracted with ethyl acetate (2 x 10 mL). The combined organic layers were washed with saturated aqueous NaCl solution (2 x 10 mL), dried over anhydrous Na2SO4, filtered, and the solvent was removed in vacuo. The residue was purified through silica gel column chromatography (hexane/ethyl acetate = 65:35) to afford 140 mg (0.34 mmol, 40%) of 9 as a white solid.