反应详情

温度

-40 °C

A solution of Example 191E (1.50 g, 7.56 mmol) in dry tetrahydrofuran (38 mL) at −40° C. was treated dropwise with a solution of n-butyllithium in hexanes (2.5 M, 3.93 mL, 9.83 mmol). After addition of the n-butyllithium, the solution took on a distinct light orange color. The solution was stirred at −40° C. for 45 minutes, followed by dropwise addition of a solution of iodine (2.69 g, 10.59 mmol) in dry tetrahydrofuran (18 mL) followed by warming to room temperature for 20 minutes. The solution was treated with water and with vigorous stirring, solid sodium sulfite was added to discharge the iodine color. The mixture was diluted with ethyl acetate and extracted with water and saturated sodium chloride solution. Drying (Na2SO4), filtration, and concentration in vacuo afforded an oil, which was chromatographed over a 220 g silica gel cartridge, eluting with 0-20% acetonitrile in chloroform. These procedures afforded the title compound (840 mg, 34%) as a colorless oil that crystallized upon pumping under high vacuum. MS (ESI+) m/z (rel abundance) 325 (100, M+H)+, 326 (12).

1. temperatureby warming to room temperature for 20 minutes
2. additionwas added
3. extractionextracted with water and saturated sodium chloride solution
4. customDrying
5. filtration(Na2SO4), filtration, and concentration in vacuo
6. customafforded an oil, which
7. customwas chromatographed over a 220 g silica gel cartridge
8. washeluting with 0-20% acetonitrile in chloroform