Abstract: Firstly 1-acetyl-5,5-dimethyl-1-cyclohexene was obtained via rearrangement cyclization reaction with dehydrolinalool as starting material and poly-phosphoric acid (PPA) as catalyst,and then via the alkylation reaction to synthesize the targeted product dynascone.The overall yield of the two steps achieves 40.8%.The product was characterized by IR,¹HNMR,¹³CNMR and GC-MS.Effect of dosage of the catalyst,reaction temperature and catalyst reusing on yield of 1-acetyl-5,5-dimethyl-1-cyclohexene was investigated.Results showed that yield of 1-acetyl-5,5-dimethyl-1-cyclohexene achieves 97.0% based on 80 ℃ of reaction temperature and mass ratio of dehydrolinalool to PPA 1:2.The catalyst PPA can be reused for 2~3 times.

Key words: dynascone, dehydrolinalool, poly-phosphoric acid