To an ice-cooled flask containing 116 gm (1.0 mole) of n-caproic acid is added 21.0-23.10 gm (0.5-0.55 mole) of ketene at a rate of 0.45 mole/hr. The reaction mixture is fractionally distilled at atmospheric pressure to afford a forecut of acetone, acetic acid, and acetic anhydride. The oil bath is raised to 220°C over a 1-hr period, kept there for 3 hr to ensure complete removal of acetic acid, and then cooled. The distillation is continued under reduced pressure to afford 86-95 gm (80-87%), b.p. 109- 112°C (3 mm Hg) and b.p. 118-121°C (6 mm Hg).
