反应详情

温度

0 °C

3-Phenyl-5H-furan-2-one (Description 2; 4.5 g, 0.028 mol), and acetone cyanohydrin (3.06 ml) were dissolved in CH3CN (80 ml) and cooled to −0° C. Tetramethylguanidine (3.5 ml) was added dropwise over 15 minutes and the reaction left to stand for a further 15 minutes. 0.5M HCl (100 ml) was added and the reaction mixture de-colourised and the product extracted with ethyl acetate (2×40 ml), washed with brine (2×30 ml) and dried over MgSO4. The solvent was removed in vacuo to afford a brown oil which was a mixture of the cis and trans isomers. Purification was carried out using flash column chromatography on silica gel eluting in increasing concentrations of ethyl acetate in hexane (0-60%) to yield the title compound (2.93 g, 56%). The only isolated product from the column was the more thermodynamically stable trans isomer.

1. waitthe reaction left
2. extractionthe reaction mixture de-colourised and the product extracted with ethyl acetate (2×40 ml)
3. washwashed with brine (2×30 ml)
4. dry with materialdried over MgSO4
5. customThe solvent was removed in vacuo
6. customto afford a brown oil which
7. additiona mixture of the cis and trans isomers
8. customPurification
9. temperaturein increasing concentrations of ethyl acetate in hexane (0-60%)