3,4-dihydro-2H-pyran → 2-(3-Bromopropoxy)tetrahydro-2H-pyran

Participants

Reaction Steps

13.9 g (0.1 mol) of 3-bromopropan-1-ol are mixed with 400 ml of dry dichloromethane and 45.7 ml (0.5 mol) of dihydropyran are added. While stirring and if needed cooling in an ice bath 190 mg (1 mmol) of p-toluenesulfonic acid monohydrate are added in such a way that the temperature of the reaction solution does not exceed 25° C. Subsequently the reaction mixture is left for 2 hours at room temperature and extracted with half-saturated aqueous sodium hydrogen carbonate solution, the dichloromethane phase is washed twice with water, dried with magnesium sulfate and filtered to remove the drying agent and the solvent is distilled off in vacuo. The remaining oil is fractionally distilled in vacuo via a 20 cm Vigreux column. 14.2-16.4 g (65-75%) of colorless oil are obtained, which boils at from 60° to 65° C. (0.5-1 mbar).

Provenance & Evidence