反应详情

温度

0 °C

To a solution of Example 68A (7.9 g, 36.6 mmol) in tetrahydrofuran (100 mL) cooled to −78° C. under nitrogen was added butyllithium (1.6M in hexanes, 37 ml, 59.2 mmol) drop wise over 10 minutes. The reaction was stirred for 20 minutes and trimethyl borate (6.7 mL, 59.2 mmol) was added drop wise over 5 minutes. The resulting mixture was stirred for 2 hours at −78+ C. and peracetic acid (32% in acetic acid, 13 mL, 59.2 mmol) was added. After 10 minutes at −78° C. the reaction was warmed to 0° C. and stirred for 1 hour. The reaction was cooled to −10° C. and treated with 10% aqueous sodium bisulfite (30 mL). The mixture was concentrated to ⅓ volume and extracted with ether (300 mL). The organic phase was washed with water (300 mL) and brine (200 mL), dried (MgSO4), filtered, and concentrated to provide 5.2 g of the title compound (92%) as a light yellow liquid. 1H NMR (300 MHz, DMSO-d6) δ ppm 1.23 (d, J=6.25 Hz, 6H) 4.95-5.17 (m, 1H) 6.57 (d, J=8.82 Hz, 1H) 7.14 (dd, J=8.82, 2.94 Hz, 1H) 7.65 (d, J=2.94 Hz, 1H) 9.21 (s, 1H); MS (DCI) m/z 154.0 (M+H)+.

1. stirringThe resulting mixture was stirred for 2 hours at −78+ C
2. stirringstirred for 1 hour
3. temperatureThe reaction was cooled to −10° C.
4. concentrationThe mixture was concentrated
5. extractionextracted with ether (300 mL)
6. washThe organic phase was washed with water (300 mL) and brine (200 mL)
7. dry with materialdried (MgSO4)
8. filtrationfiltered
9. concentrationconcentrated