反应详情

To a solution of 4 (15.9 g, 36.3 mmol) in CH2Cl2 (30 mL) was added TFA (trifluoroacetic acetic acid) (30 mL) and the solution stirred at room temperature for 3 hours under N2. The reaction was transferred to a beaker (1 L) and diluted with CH2Cl2 (60 mL). To the solution at 0° C. was added solid NaHCO3 (39 g, 46 mmol) and stirred for 15 minutes'before partitioning between EtOAc (300 mL) and H2O (300 mL). After extraction the aqueous layer was acidified to pH 4-5 and extracted with EtOAc. The organic layer was dried (MgSO4) and evaporated to dryness to give 5 as a white solid (14.0 g, quantitative yield): 1H-NMR (500 MHz, CDCl3) δ1.08 (s, 9H), 1.97-2.22 (m, 3H), 2.29-2.41 (m, 1H), 3.71-3.78 (m, 1H), 3.90-3.98 (m, 1H), 4.55-4.62 (m, 1H), 4.86 (d, 1H), 6.64 (d, 1H), 6.74 (d, 1H), 7.53 (d, 1H), 7.74 (s, 1H). Analytical HPLC (cyano column): 8.24 min. LC-MS (ES+) m/e=382.4 (M+H).

1. stirringstirred for 15 minutes'
2. custombefore partitioning between EtOAc (300 mL) and H2O (300 mL)
3. extractionAfter extraction the aqueous layer
4. extractionextracted with EtOAc
5. dry with materialThe organic layer was dried (MgSO4)
6. customevaporated to dryness