反应详情

To a solution of (R)-2,2-dimethyl-1,3-dioxolane-4-carbaldehyde oxime (10.3 g, 71.0 mmol) in 40 mL DMF was added 1-chloropyrrolidine-2,5-dione (10.4 g, 78.1 mmol) and the reaction was stirred overnight at ambient temperature. The reaction mixture was poured into ether (1400 mL) and water (500 mL). The ether layer was extracted with water (5×500 mL), dried over MgSO4, filtered and concentrated to (S)-N-hydroxy-2,2-dimethyl-1,3-dioxolane-4-carbimidoyl chloride (10.0 g, 55.7 mmol, 78.5% yield) as white solid. Step C: A solution of (S)-N-hydroxy-2,2-dimethyl-1,3-dioxolane-4-carbimidoyl chloride (9.88 g, 55.01 mmol) in THF (200 mL) at 0° C. was added methanesulfonyl chloride (4.703 ml, 60.51 mmol), followed by N,N-diisopropylethylamine (10.54 ml, 60.51 mmol) and the reaction was stirred for 1 hour at ambient temperature, filtered and concentrated in vacuo. The residue was purified over silica gel (25 to 100% ethyl acetate in hexanes) to afford (S)-2,2-dimethyl-N-(methylsulfonyloxy)-1,3-dioxolane-4-carbaldehyde chloride (12.28 g, 47.65 mmol, 86.63% yield) as colorless oil.

1. extractionThe ether layer was extracted with water (5×500 mL)
2. dry with materialdried over MgSO4
3. filtrationfiltered