Pyridine, hydrofluoride (1:1) → HCID 67588407, compound

Participants

Reaction Steps

To a 0° C. solution of 650 mg (0.82 mmol) 5-{(2R)-2-[[(2R)-2-(tert-butyl-dimethyl-siloxy)-2-(3-chloro-phenyl)-ethyl]-(2,2,2-trichloro-ethoxycarbonyl)-amino]-propyl}-benzo[1,3]dioxole-2,2-dicarboxylic acid diallyl ester and 20 mL THF was added 1.0 mL of HF·pyridine, and the reaction mixture was warmed to room temperature. After 22 h, TLC indicated that some starting material remained (Rf =0.62 (2/1 hexanes/EtOAc), and an additional 1.0 mL of HF·pyridine was added. After a total of 26 h, TLC indicated the disappearance of starting material and the formation of the title compound (Rf =0.28 (2/1 hexanes/EtOAc). The reaction mixture was slowly quenched with 30 mL of sat. aq. NaHCO3, extracted with 2×75 mL Et2O and then with 1×75 mL EtOAc. The combined organics were washed with 1×100 mL brine, dried over MgSO4, filtered and evaporated to a colorless oil. Flash chromatography on silica gel, eluting with hexanes/EtOAc (2/1), gave 460 mg (0.68 mmol, an 83% yield) of the title compound (Rf =0.28; 2/1 hexanes/EtOAc) as a colorless oil; 1H NMR (300 MHz, CDCl3): δ 1.20-1.37 (m, 3H), 2.60-2.78 (m, 2H), 2.80-2.91 (m, 1H), 2.98-3.18 (m, 1H), 3.23-3.40 (m, 1H), 3.41-3.54 (m, 2H), 4.10-4.26 (br m, 1H), 4.73-4.92 (5H), 5.22-5.40 (complex m, 4H), 5.81-5.98 (complex m, 2H), 6.62-6.87 (m, 4H), 7.17-7.41 (m, 3H); MS (ES) m/z (relative intensity): 700 (M+ +Na, 100).

Provenance & Evidence