Pyridine → rac. E-8-benzyloxy-3,7-dimethyl-4-octenal

Participants

Reaction Steps

To a solution of 1.19 g. of pyridine in 15 ml. of dichloromethane was added0.6 g. (6 mmoles) of chromium trioxide. The brown mixture was stirred at room temperature for 15 minutes, then treated with a solution of rac. E-8-benzyloxy-3,7-dimethyl-4-octen-1-ol (0.262 g.; 1 mmole) in 3 ml. of dichloromethane. After stirring at room temperature for 15 minutes, the dichloromethane solution was decanted from the dark tarry residue then theresidue was washed three times with fresh dichloromethane. The dichloromethane solutions were combined and washed with 1 N aqueous sodiumhydroxide, 1 N aqueous hydrochloric acid, saturated aqueous sodium bicarbonate solution and brine then dried, filtered and concentrated in vacuo. The residue (0.255 g.) was chromatographed on 10 g. of silica gel. Elution with 9:1 parts by volume and 4:1 parts by volume hexane-ether gave0.196 g. (75.5%) of pure rac. E-8-benzyloxy-3,7-dimethyl-4-octenal. Evaporative distillation yielded a colorless liquid, b.p. 90° -93° C. (bath temperature) (0.1 mm Hg.).

Provenance & Evidence