Preparation method of 2-n-pentylcyclopentyl-2-ketene

The invention discloses a preparation method of 2-n-pentylcyclopentyl-2-ketene, and particularly relates to the technical field of perfume production, and the preparation method comprises the following steps: step 1, adding 2-pentylidene cyclopentanone, a solvent, an auxiliary agent and protonic acid into a reaction container, stirring, heating to a certain temperature, keeping the temperature for a certain time, and keeping the temperature until the reaction is finished; and 2, cooling to room temperature, adding a certain amount of alkali for neutralization, washing with water, desolventizing, and carrying out reduced pressure distillation to obtain the finished product 2-pentylcyclopentyl-2-ketene. According to the invention, a catalytic amount of auxiliary agent and protonic acid are used, the process condition is mild, the equipment corrosion is greatly reduced, and the safety of the equipment is improved. Acid with a catalytic amount is adopted, so that the generation amount of salt-containing wastewate