反应详情

According to the procedure by Flader et al.,22 lithium aluminum hydride (0.855 g, 21.4 mmol) was added to a flame-dried 250 mL round bottom flask under argon to which dry THF (150.0 mL) was added at room temperature. Ester 25 (5.05 g, 20.5 mmol) was then dissolved in THF (50.0 mL) and added slowly at room temperature under argon, and the reaction was stirred at room temperature for 8 hours. The reaction was then quenched by adding H2O (1.0 mL) dropwise at 0° C., followed by 2 M NaOH (2.0 mL), and then H2O (3.0 mL). The resulting suspension was then filtered and the filtrated was acidified with dilute HCl, washed with saturated brine, dried over MgSO4, and filtered. The condensed filtrate resulted in a crude solid that could be purified by flash column chromatography (7:13 EtOAc:hexanes) or recrystallization from Et2O/hexanes to afford 26 (4.34 g, 19.9 mmol, 97%) as long white needles.

1. additionwas added at room temperature
2. additionadded slowly at room temperature under argon
3. customThe reaction was then quenched
4. additionby adding H2O (1.0 mL) dropwise at 0° C.
5. filtrationThe resulting suspension was then filtered
6. washwashed with saturated brine
7. dry with materialdried over MgSO4
8. filtrationfiltered
9. customThe condensed filtrate resulted in a crude solid that
10. customcould be purified by flash column chromatography (7:13 EtOAc:hexanes) or recrystallization from Et2O/hexanes