反应 #5655

反应方程式

diborane

2-valeryl furan

[1,3,2] oxazaborole

HCl

→

product

收率 70.0%

(S)-1-(2-Furyl)-1-pentanol

收率 70.0%

溶剂

methanol

THF

ether

反应条件

后处理

1. 1
   workup.STIRRINGStirred for 0.5 h
2. 2
   其他white solid was precipitated out
3. 3
   workup.ADDITIONThe cloudy mixture was poured into 100 mL ether and 100 mL water
4. 4
   其他The organic layer was separated
5. 5
   洗涤washed with saturated sodium bicarbonate, water, brine
6. 6
   其他dried
7. 7
   过滤filtered
8. 8
   其他The filtrate was evaporated to an yellowish oil which
9. 9
   其他was chromatographed
10. 10
    洗涤eluting with 10 % ethyl acetate in hexane

实验过程

10.4 mmol (10.4 mL) of diborane (1 M solution in THF) was added dropwise in a period of 10 m at room temperature to a solution of 2-valeryl furan (2.62 g, 17.2 mmol) and 1.68 mmol (4.2 mL) of (3aR)-1,3,3-triphenyl pyrrolidino [1,2-c] [1,3,2] oxazaborole (see E. J. Corey et al. J. Am. Chem. Soc. 1987, 109, 7925-26, 0.4M solution in THF) in 25 mL THF. The reaction mixture was stirred for 20 m and was cooled to 10° C. 6 mL methanol was cautiously added and followed by adding 62 mg HCl (by weight) in ether. Stirred for 0.5 h, white solid was precipitated out. The cloudy mixture was poured into 100 mL ether and 100 mL water. The organic layer was separated, washed with saturated sodium bicarbonate, water, brine, dried and filtered. The filtrate was evaporated to an yellowish oil which was chromatographed eluting with 10 % ethyl acetate in hexane to obtain 70% of the product. [α]25D =-13°, 60% ee by Mosher' ester analysis.

来源