反应详情

A solution of dimethyl homoterephthalate (7, R=H) (4.16 g, 20 mmole) in 15 ml of dry tetrahydrofuran was added dropwise over 15 minutes to a stirred mixture of potassium hydride (2.5 g of 35% oil suspension, 22 mmole) in 75 ml of dry tetrahydrofuran at 0° C. After 30 minutes a homogeneous yellow suspension had formed. Methyl iodide (2.79 g, 22 mmole) was then added over a 5 minute period and the resulting mixture stirred for 30 minutes. The mixture was quenched with 2 ml of 50% acetic acid, diluted with 500 ml of water and extracted with ether. The ether extract was washed with water, dried over magnesium sulfate and evaporated to leave an oil. The material was chromatographed on silica gel with elution by ether-hexane (1:9) to afford (71%) of a clear oil; m/e 222 (M+): NMR (CDCl3) 1.50 (3H, d, CH3), 3.65 (3H, s, OCH3), 3.93 (3H, s, OCH3 benzoate).

1. customAfter 30 minutes a homogeneous yellow suspension had formed
2. customThe mixture was quenched with 2 ml of 50% acetic acid
3. additiondiluted with 500 ml of water
4. extractionextracted with ether
5. extractionThe ether extract
6. washwas washed with water
7. dry with materialdried over magnesium sulfate
8. customevaporated
9. customto leave an oil
10. customThe material was chromatographed on silica gel with elution by ether-hexane (1:9)