反应详情

Tert-butyl((3aR,4R,6aR)-5-fluoro-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-yloxy)diphenylsilane (5-5) (840 mg, 2.0 mmol, 1 eq) was dissolved in THF (10 mL) and TBAF (4.0 mL, 4.0 mmol, 2 equiv, 1M in THF) was added. The resulting mixture was stirred at ambient temperature for 2 hours. Upon disappearance of the starting material, the mixture was diluted with 50 mL EtOAc and washed with water (3×20 mL) and brine (20 mL). The organic layer was dried over MgSO4, filtered and concentrated. The crude residue was purified by flash chromatography (40 g SiO2, 0-60% EtOAc in hexanes) to yield (3aS,4R,6aR)-5-fluoro-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-ol (5-6) as a colorless oil. 1H NMR (500 MHz, CDCl3): δ 5.31 (s, 1H); 4.98 (td, J=6.0, 2.0 Hz, 1H); 4.74 (td, J=6.0, 3.0 Hz, 1H); 4.44 (s, 1H); 2.88 (brs, 1H); 1.49 (s, 3H); 1.41 (s, 3H).

1. washwashed with water (3×20 mL) and brine (20 mL)
2. dry with materialThe organic layer was dried over MgSO4
3. filtrationfiltered
4. concentrationconcentrated
5. customThe crude residue was purified by flash chromatography (40 g SiO2, 0-60% EtOAc in hexanes)