反応 #2358495

反応方程式

2-Chloro-4-methyl-2H-furan-5-one

LDA

1-Phenylazepan-2-one

ethylformate

→

(3E)-3-[(4-methyl-5-oxo-2H-furan-2-yl)oxymethylene]-1-phenyl-azepan-2-one

溶媒

ethyl acetate

Water

tetrahydrofuran

反応条件

後処理

1. 1
   温度the reaction mixture was warmed up to −40° C.
2. 2
   workup.STIRRINGstirred for 5 min
3. 3
   温度The mixture was warmed up to 0° C.
4. 4
   workup.STIRRINGstirred for another 30 min
5. 5
   温度The reaction mixture was warmed up to room temperature
6. 6
   workup.STIRRINGstirred for 3 h
7. 7
   その他the layers were separated
8. 8
   抽出The aqueous layer was extracted with ethyl acetate
9. 9
   洗浄washed with water and brine
10. 10
    乾燥dried over Na2SO4
11. 11
    その他the solvent was evaporated
12. 12
    その他to give a brown residue which
13. 13
    その他was purified by flash chromatography (0-100% ethyl acetate in cyclohexane)

実験手順

1-Phenylazepan-2-one (0.500 g, as prepared in Organic Letters 2000, pages 1101-1104) was dissolved in tetrahydrofuran (30 mL) and cooled to −78° C. To the solution was added LDA (2.0 mol/L in THF/heptane/ethylbenzene, 2.6 mL) dropwise. After stirring for 10 min between −55 and −50° C., the reaction mixture was warmed up to −40° C., stirred for 5 min and ethylformate (0.657 mL, 0.605 g) was added slowly. The mixture was warmed up to 0° C. and stirred for another 30 min. 2-Chloro-4-methyl-2H-furan-5-one (0.420 g in 2 mL of THF) was added dropwise. The reaction mixture was warmed up to room temperature and stirred for 3 h. Water and ethyl acetate were added and the layers were separated. The aqueous layer was extracted with ethyl acetate, the organic layers were combined, washed with water and brine, dried over Na2SO4 and the solvent was evaporated to give a brown residue which was purified by flash chromatography (0-100% ethyl acetate in cyclohexane). (3E)-3-[(4-methyl-5-oxo-2H-furan-2-yl)oxymethylene]-1-phenyl-azepan-2-one Ic-13 (0.103 g, 11%) was obtained as a white solid; mp: 150-160° C.; LCMS (Method D): 0.91 min; ES+314 (M+H+).

出典