反应详情

To a stirred solution of oxalyl chloride (0.43 mL, 5.0 mmol) in CH2Cl2 (30 mL) at −78° C. is added DMSO (0.52 mL, 7.0 mmol) dropwise. After gas evolution subsided (5 min), the alcohol of Example 4 (0.8 g, 3.5 mmol) in CH2Cl2 (20 mL) is added in a stream. After 20 min, (carbethoxymethylene) triphenyl-phosphorane (1.4 g, 4.0 mmol) is added. After 2 h, the reaction mixture is diluted with petroleum ether, washed with water, 5% KHSO4 and sat. NaCl, dried over MgSO4, and concentrated. Flash column chromatography (15% EtOAc in hexane) gave the title compound (0.57 g, 38%) as a colorless oil.

1. custom(5 min)
2. waitAfter 2 h
3. washwashed with water, 5% KHSO4 and sat. NaCl
4. dry with materialdried over MgSO4
5. concentrationconcentrated