反应详情

To a solution of 5-methylcyclohexane-1,3-dione (1.79 g, 14.0 mmol) in 20 ml of methylene chloride containing triethylamine (2.90 ml, 20.8 mmol) is added, dropwise at 0°, a solution of 2-chloro-4-methylsulfonyloxybenzoyl chloride, prepared from the corresponding acid (3.50 g, 14.0 mmol) and thionyl chloride, in methylene chloride (10 ml). After the addition is complete, the mixture is stirred for another 30 min. at 0°, after which it is diluted with methylene chloride, washed, dried and evaporated to dryness. The crude enol ester is treated with triethylamine (3.97 ml, 2 eq.) and acetone cyanohydrin (0.4 ml) in 25 ml of acetonitrile. After stirring overnight at RT, the reaction mixture is concentrated and poured into water. The combined organic extracts are washed with dilute HCl and with brine, dried and evaporated to dryness. The crude product is crystallized from ether to give 2-(2-chloro-4-methylsulfonyloxybenzoyl)-5-methyl-cyclohexane-1,3-dione.

1. additionis added, dropwise at 0°
2. additionAfter the addition
3. washwashed
4. customdried
5. customevaporated to dryness
6. stirringAfter stirring overnight at RT
7. concentrationthe reaction mixture is concentrated
8. additionpoured into water
9. washThe combined organic extracts are washed with dilute HCl and with brine
10. customdried
11. customevaporated to dryness
12. customThe crude product is crystallized from ether