反应 #657297

反应方程式

HCl

DCM

n-BuLi

pinanediol

B(OEt)3

→

Intermediate 1

收率 65.7%

(3aS,4S,6S)-2-(dichloromethyl)-3a,5,5-trimethylhexahydro-4,6-methano-1,3,2-benzodioxaborole

收率 65.7%

溶剂

THF

diethyl ether

反应条件

后处理

1. 1
   workup.STIRRINGthe mixture was stirred for 1 h at −45° C. to −30° C
2. 2
   温度while maintaining the temperature below −20° C.
3. 3
   workup.STIRRINGthe resulting mixture was stirred at −20° C. for 4 h
4. 4
   其他The organic layer was separated
5. 5
   萃取the water layer was extracted with diethyl ether (100 mL×2)
6. 6
   干燥The combined organic layers were dried over anhydrous Na2SO4
7. 7
   浓缩concentrated
8. 8
   其他to give an intermediate
9. 9
   workup.STIRRINGThe reaction mixture was stirred overnight at room temperature
10. 10
    浓缩concentrated in vacuo
11. 11
    其他The residue was purified by column chromatography (petroleum ether:EtOAc 10:1 to 1:1)

实验过程

To a solution of DCM (80 mL, 1.2 mol) in THF (800 mL) at −80° C. to −90° C. was added n-BuLi (2.5 M in hexane, 480 mL, 1.2 mol) under N2, and the reaction mixture was stirred for 1.5 h below −80° C. B(OEt)3 (200 mL, 1.2 mol) was added in one portion and the mixture was stirred for 1 h at −45° C. to −30° C. Aqueous HCl (5 M, 240 mL, 1.2 mol) was then added dropwise while maintaining the temperature below −20° C. and the resulting mixture was stirred at −20° C. for 4 h. The organic layer was separated, and the water layer was extracted with diethyl ether (100 mL×2). The combined organic layers were dried over anhydrous Na2SO4 and concentrated to give an intermediate. The intermediate was re-dissolved in diethyl ether (800 mL) and pinanediol (188 g, 1.1 mol) was added to the solution. The reaction mixture was stirred overnight at room temperature and then concentrated in vacuo. The residue was purified by column chromatography (petroleum ether:EtOAc 10:1 to 1:1) to afford Intermediate 1 (190 g, 60% yield).

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