Lithium bis(trimethylsilyl)amide (3.46 mmol, 1M in THF) was added dropwise to a solution of methyl trimethylsilylacetate (3.46 mmol) in THF (5 mL) at −78° C. After 20 minutes at −78° C., a solution of 10.2 (2.16 mmol) in THF (9 mL) was added dropwise and the reaction was maintained at −78° C. for 1.5 hours. The reaction was quenched with water and extracted with EtOAc. The organic phase was washed with brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was chromatographed (silica gel, 1:1 EtOAc/hexane) to afford compound 10.3. MS ESI (pos.) m/e 330.1 (M+1).
