反应详情

For the first stage, a solution of (−)-menthol (1.56 g, 10 mmol), 2-bromoacetic acid (1.39 g, 10 mmol) and monohydrated p-toluenesulphonic acid (0.5 g, 2.6 mmol) was brought to reflux for 3 h in 100 ml toluene. The water given off during the reaction is separated by azeotropic distillation. 100 ml toluene is added, and the mixture is washed 3 times with 10 ml of a 5% NaOH solution, then twice with 100 ml of brine, the organic solvent is dried on Na2SO4 and the solvent evaporated under vacuum. The menthyl 2-bromoacetate obtained (2.45 g, 89%) is used in the next step without purification.

1. customis separated by azeotropic distillation
2. addition100 ml toluene is added
3. washthe mixture is washed 3 times with 10 ml of a 5% NaOH solution
4. dry with materialtwice with 100 ml of brine, the organic solvent is dried on Na2SO4
5. customthe solvent evaporated under vacuum