反应详情

To a stirred solution of oxalyl chloride (0.43 mL, 5.0 mmol) in CH2Cl2 (20 mL) at -78° C. was added DMSO (0.52 ml, 7.0 mmol) dropwise. After gas evolution subsided (~5 minutes) the alcohol 17 (0.8 g, 3.5 mmol) in CH2Cl2 (20 mL) was added in a stream. After 20 minutes triethylamine (1.7 mL, 12 mmol) was added dropwise and then the cooling bath removed. After 20 minutes (carbethoxymethylene) triphenylphosphorane (1.4 g, 4.0 mmol) was added. After 2.0 hours the reaction mixture was diluted with petroleum ether and then washed sequentially with H2O, 5% KHSO4, and brine, dried (MgSO4) and concentrated. Flash chromatography (silica, 15% ethyl acetate/hexanes) gave the ester 18 (0.57 g) as a colorless oil.

1. custom(~5 minutes)
2. additionwas added in a stream
3. customthe cooling bath removed
4. washwashed sequentially with H2O, 5% KHSO4, and brine
5. dry with materialdried (MgSO4)
6. concentrationconcentrated