反応 #426806

反応方程式

triisopropyl borate

n-BuLi

hexane

2-[2-bromo-3-(4-methoxy-benzyloxy)-benzyloxy]-tetrahydro-pyran

HCl

→

7-(4-Methoxy-benzyloxy)-3H-benzo[c][1,2]oxaborol-1-ol

溶媒

THF

反応条件

後処理

1. 1
   workup.STIRRINGstirred at −78° C. (bath temp) for 4 h
2. 2
   温度to warm up to 0° C. (bath temp)
3. 3
   workup.STIRRINGThe mixture was stirred for 3 h
4. 4
   その他the resulting precipitate was isolated by filtration
5. 5
   洗浄washed with 1:9 CH2Cl2/Et2O
6. 6
   その他to give A25 as a yellow solid

実験手順

2.5 M n-BuLi in hexane (1.53 mL, 3.83 mmol) was added dropwise to a solution of 2-[2-bromo-3-(4-methoxy-benzyloxy)-benzyloxy]-tetrahydro-pyran (1.3 g, 3.2 mmol) in THF (14 mL) under N2 at −78° C. (bath temp). The mixture was stirred at −78° C. (bath temp) for 2 h then triisopropyl borate (0.90 mL, 3.8 mmol) was added slowly and stirred at −78° C. (bath temp) for 4 h. The mixture was allowed to warm up to 0° C. (bath temp) and then acidified with 3 M HCl to pH 5. The mixture was stirred for 3 h and the resulting precipitate was isolated by filtration and washed with 1:9 CH2Cl2/Et2O to give A25 as a yellow solid: yield 0.10 g (12%).

出典