Acetaldehyde → 1-(p-Prenylphenyl)ethanol

Participants

Reaction Steps

Under a nitrogen atmosphere, 9.6 g of magnesium turnings, 30 ml of tetrahydrofuran and about 50 mg of iodine were put in a flask. With stirring, 2 ml of ethyl bromide was added, whereupon coloration by iodine disappeared. With stirring, the mixture was heated and maintained at 110° C. to 120° C., and 60 g of p-chloroprenylbenzene was added. During the reaction, 20 ml of tetrahydrofuran was further added. After continuing the reaction for 4.5 hours, the reaction mixture was cooled to room temperature, and 200 ml of tetrahydrofuran was added. A solution of 22.0 g of acetaldehyde in 30 ml of tetrahydrofuran was added at 5° C. to 10° C. over the course of about 2 hours. After the addition, the mixture was stirred for 1 hour, and then 400 ml of a 10% by weight aqueous solution of ammonium chloride was added. The mixture was separated into an organic layer and an aqueous layer. The aqueous layer was extracted with 30 ml of diethyl ether. The diethyl ether layer was combined with the organic layer previously separated and washed with water, dried, concentrated and distilled to give 47.3 g (yield 74.9%) of 1-(p-prenylphenyl)ethanol having a boiling point of 108° C. to 110° C./0.5 mmHg. The nuclear magnetic resonance spectrum of the product was as follows. (The chemical shifts are expressed in δ (ppm) when hexamethylsiloxane is used as a standard.)

Provenance & Evidence