Jasmonone is one of the most valuable spices. Its fragrance is very similar to jasmine. It is one of the most important components of jasmine oil. It is used in the Jasmine Series flavor. Dihydrojasmonane can be obtained by hydrogenation and reduction of jasmonane. Two hydrogen jasmonone is a slightly colored transparent liquid, with boiling point of 230 degrees, 102 degrees (0.67kPa), with strong fragrance and stable chemical properties. It can be widely used in jasmine flavor series, and two hydrogen jasmonone is simple in industrial production. Dihydrojasmonane can be prepared by cyclizing undecanoic acid in the presence of phosphoric acid at 80 ℃ and pressure of 0.007-0.011mpa.