Dichloroacetyl chloride → 7,7-Dichloro-4-(5-methoxyheptyl)bicyclo[3.2.0]heptan-6-one

Participants

Reaction Steps

To a 1,000 ml three-necked, round-bottomed flask, equipped with a reflux condenser containing 3-(5-methoxyhept-1-yl)cyclopentene {3-(5-methoxyheptyl)cyclopentene} (15.0 g, 0.076 moles) in 300 ml of hexane, freshly distilled dichloroacetyl chloride (35.1 g, 0.240 moles) is added and the solution is stirred by a mechanical stirrer and heated to reflux. Triethylamine (25.2 g, 0.249 moles), dissolved in 200 ml hexane, is added dropwise and the refluxing solution allowed to stir for 4 hours. The solvent is removed and then the residue is distilled and applied to a silica gel chromatography column of 4.5 cm diameter in a 4:1 hexane-ether solvent mixture. The product is eluted using a 4:1 hexane-ether solvent system. The fractions are monitored using vapor phase chromatography. The solvent is removed under vacuum. 6,6-Dichloro-2-(5-methoxyhept-1-yl)bicyclo[3.2.0]heptan-7-one {7,7-dichloro-4-(5-methoxyheptyl)bicyclo[3.2.0]heptan-6-one} and a smaller amount of 7,7-dichloro-(5-methoxyhept-2-yl)bicyclo[3.2.0]heptan-6-one {7,7-dichloro-2-(5-methoxyheptyl)bicyclo[3.2.0]heptan-6-one} were obtained in mainly the alpha form .

Provenance & Evidence