1,2-Dibromoethane → 6-Hydroxy-6-methylheptyl 2-tetrahydropyranyl ether

Participants

Reaction Steps

A small portion of a solution of the product from Step I (21.1 g, 0.102 mol) in THF (105 ml) was added, under nitrogen, to magnesium turnings (5.0 g, 0.204 g-atom). The mixture was warmed in an oil bath at 75°-80° and the reaction was started by the addition of 1.5 ml of a 1M solution of 1,2-dibromoethane in THF. The remaining chloroalkane solution was then added during 20 minutes. The resulting mixture was refluxed for 45 minutes, cooled in an ice bath and treated during 15 minutes with a solution of acetone (9.0 ml, 0.123 ml) in THF (95 ml). It was kept at ambient temperature for 16 hours, cooled in an ice bath and treated during 15 minutes with saturated aqueous NH4Cl (115 ml). The resulting mixture was extracted with EtO. The extract was washed with water and brine, dried (MgSO4) and concentrated to give 30.5 g of crude product. Distillation gave 16.77 g of 6-hydroxy-6-methylheptyl 2-tetrahydropyranyl ether, bp 107°-115° (0.07-0.1 mm Hg). The CI mass spectrum had m/z 231 (M+H)+.

Provenance & Evidence