Water → 2-(7-Chloroheptyl)-2-cyclopentenone

Participants

Reaction Steps

The following procedure was adopted from H. Hayaski et al., J. Amer. Chem. Soc., 95, 8749 (1972): To a solution containing 643 mg (3.28 mmol) of 2-(7-hydroxyheptyl)-2-cyclopentenone in 0.47 ml carbon tetrachloride at 35° (temperature of the external water bath), under argon, was added, dropwise over 1 hour, a solution containing 860 mg (3.28 mmol) triphenylphosphine in 3 ml of anhydrous methylene chloride. The yellow solution was stirred for an additional 4.0 hours at ca. 35° and overnight at reflux. The resultant brown residue was taken up in hot hexane and filtered through a sintered glass funnel containing a pad of Celite whereupon the filtrate was reduced in volume and column chromatographed using an 80% silicic acid-20% Celite column and benzene to 80% benzene-20% ethyl acetate in a gradient elution (5 ml fractions). Thus 2-(7-chloroheptyl)-2-cyclopentenone was obtained (20.2 mg) as a pale orange oil.

Provenance & Evidence