反応 #162924

反応方程式

Na2CO3

Na2CO3

tert-butyl ((3S,7S,8R,9S)-7-benzyl-8-((tert-butyldimethylsilyl)oxy)-9-methyl-2-oxo-1,5-dioxonan-3-yl)carbamate

pyridine THF

HF-pyridine

→

tert-butyl-(3S,7S,8R,9S)-7-benzyl-8-hydroxy-9-methyl-2-oxo-1,5-dioxonan-3-ylcarbamate

収率 90.0%

溶媒

EtOAc

反応条件

後処理

1. 1
   その他The crude reaction
2. 2
   workup.ADDITIONwas added
3. 3
   その他until bubbling
4. 4
   その他The EtOAc layer was separated
5. 5
   抽出the aqueous phase was extracted with EtOAc (2×)
6. 6
   乾燥The combined organic layers were dried over Na2SO4
7. 7
   ろ過filtered
8. 8
   濃縮concentrated

実験手順

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]).

出典