Isopropanol → 1-Isopropoxy-1-cyclopentene

Participants

Reaction Steps

A mixture of 84.12 grams (1 mol) of cyclopentanone, 195.2 grams (1.03 mol) of triisopropyl orthoformate and 60 grams of isopropanol (1 mol) was stirred in a 500 ml three-neck round bottom flask at room temperature. To this mixture, 3.8 g (0.028 mol) of sodium hydrogensulfate monohydrate was added, and the temperature of the reaction mixture was heated and maintained at 40° C. for about one hour. The progress of the reaction was monitored by GC until the cyclopentanone content was reduced to less than 2%. The isopropanol and isopropyl formate were distilled off under reduced pressure while the temperature of the reaction mixture was increased to a maximum of 65° C. The reaction mixture was cooled to room temperature and the pH value was adjusted to about 7˜8 by adding about 0.2 gram of potassium iso-propoxide. The mixture was then heated under reduced pressure to remove unreacted cyclopentanone and 64 grams (0.51 mol) of 1-isopropoxy-1-cyclopentene was isolated as a clear liquid at a yield of 51%. The purity of the product exceeded 98%.

Provenance & Evidence