反応 #657297

反応方程式

HCl

DCM

n-BuLi

pinanediol

B(OEt)3

→

Intermediate 1

収率 65.7%

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

収率 65.7%

溶媒

THF

diethyl ether

反応条件

後処理

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
   その他The organic layer was separated
5. 5
   抽出the water layer was extracted with diethyl ether (100 mL×2)
6. 6
   乾燥The combined organic layers were dried over anhydrous Na2SO4
7. 7
   濃縮concentrated
8. 8
   その他to give an intermediate
9. 9
   workup.STIRRINGThe reaction mixture was stirred overnight at room temperature
10. 10
    濃縮concentrated in vacuo
11. 11
    その他The residue was purified by column chromatography (petroleum ether:EtOAc 10:1 to 1:1)

実験手順

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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