반응 #5655

반응 방정식

diborane

2-valeryl furan

[1,3,2] oxazaborole

HCl

→

product

수율 70.0%

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

수율 70.0%

용매

methanol

THF

ether

반응 조건

후처리

1. 1
   workup.STIRRINGStirred for 0.5 h
2. 2
   기타white solid was precipitated out
3. 3
   workup.ADDITIONThe cloudy mixture was poured into 100 mL ether and 100 mL water
4. 4
   기타The organic layer was separated
5. 5
   세척washed with saturated sodium bicarbonate, water, brine
6. 6
   기타dried
7. 7
   여과filtered
8. 8
   기타The filtrate was evaporated to an yellowish oil which
9. 9
   기타was chromatographed
10. 10
    세척eluting with 10 % ethyl acetate in hexane

실험 절차

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.

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