反应详情

A solution of tert-butyl ((3S,7S,8R,9S)-7-benzyl-8-((tert-butyldimethylsilyl)oxy)-9-methyl-2-oxo-1,5-dioxonan-3-yl)carbamate (120 mg, 0.24 mmol) in a solution of HF/pyridine/THF (5:3:8 ratio, 1.2 mL) was stirred at room temperature. After 16 h, an additional 0.1 mL HF-pyridine solution was added and the reaction was allowed to stir for 2 h. The crude reaction was diluted with EtOAc (5 mL) and added to sat'd aq Na2CO3 (5 mL) dropwise. Additional sat'd aq Na2CO3 was added until bubbling was no longer observed. The EtOAc layer was separated and the aqueous phase was extracted with EtOAc (2×). The combined organic layers were dried over Na2SO4, filtered, and concentrated to furnish tert-butyl-(3S,7S,8R,9S)-7-benzyl-8-hydroxy-9-methyl-2-oxo-1,5-dioxonan-3-ylcarbamate as a colorless oil (82 mg, 89%): 1H NMR (400 MHz, CDCl3) δ 7.32-7.26 (m, 3H), 7.20 (dd, J=8.2, 6.4 Hz, 2H), 5.15 (d, J=8.5 Hz, 1H), 4.88 (m, 1H), 4.65 (d, J=7.6 Hz, 1H), 3.90 (dd, J=11.7, 7.5 Hz, 1H), 3.57 (d, J=10.3 Hz, 1H), 3.44 (m, 2H), 3.33 (m, 1H), 3.11 (dd, J=13.8, 4.3 Hz, 1H), 2.49 (m, 1H), 1.87 (s, 1H), 1.48 (d, J=6.4 Hz, 3H), 1.43 (d, J=4.3 Hz, 9H); ESIMS m/z 378.4 ([M−H]).

1. customThe crude reaction
2. additionwas added
3. customuntil bubbling
4. customThe EtOAc layer was separated
5. extractionthe aqueous phase was extracted with EtOAc (2×)
6. dry with materialThe combined organic layers were dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated