反应详情

To a solution of (triisopropylsilyl)acetylene (6.50 mL, 29.0 mmol) in THF (80 mL) at −78° C. was added n-BuLi (2.5 M in hexane, 12.2 mL, 30.4 mmol) while maintaining the internal temperature below −70° C. After 30 min., ethyl trifluoroacetate (4.14 mL, 34.8 mmol) was added dropwise, keeping the internal temperature below −73° C. After 15 min. at −78° C., the mixture was allowed to reach 0° C. After 2 h, a saturated solution of NH4Cl was added. The aqueous layer was extracted with EtOAc (3×), and the combined organic layers were washed with brine, dried (Na2SO4) and concentrated affording the title compound. 1H NMR (400 MHz, acetone-d6): 1.27 (m, 3H), 1.16 (d, 18H).

1. temperaturewhile maintaining the internal temperature below −70° C
2. customthe internal temperature below −73° C
3. waitAfter 15 min. at −78° C.
4. customto reach 0° C
5. waitAfter 2 h
6. extractionThe aqueous layer was extracted with EtOAc (3×)
7. washthe combined organic layers were washed with brine
8. dry with materialdried (Na2SO4)
9. concentrationconcentrated