Cycloheptanone → 2-[(Tetrahydropyranyloxy)acetyl]cycloheptanone

Beteiligte Stoffe

Reaktionsschritte

A solution of 2.80 g (25 mmol) of cycloheptanone and 4.71 g (25 mmol) of ethyl (tetrahydropyranyloxy)acetate (Ireland, R. E.; Wipf, P. Tetrahedron Lett., 1989, 30, 919-22) in 20 mL of Et2O was added over the course of 1 h to an ice-cold, stirring mixture of hexane-washed NaH and 0.12 mL (2 mmol, 0.092 g) of absolute EtOH in 10 mL of Et2O under N2. The light brown mixture was allowed to warm to room temperature and was stirred overnight. MeOH (5 mL) was added and the solution was poured onto 200 mL of saturated aqueous NH4Cl. After acidification to pH 2 with 1N aqueous HCl, the mixture was extracted with Et2O. The organic layer was washed with brine, dried over Na2SO4, and concentrated to give 5.61 g of crude 2-[(tetrahydropyranyloxy)acetyl]cycloheptanone as a light brown oil.

Herkunft & Nachweise