Preparation: Widely exists in natural plant essential oils. Among them, mainly containing dextroisomer have tangerine oil, lemon oil, orange oil, camphor white oil and so on.There is peppermint oil that contains levoform . The racemates include neroli oil, cedar oil and camphor white oil.When manufacturing this product,using the above-mentioned essential oils to do the fractional distillation separately.Terpenes can also be extracted from ordinary essential oils, or prepared in the process of camphor oil and camphor synthesis,produced as a secondary product. The obtained dipentene can be purified by distillation to obtain limonene. Use turpentine as a raw material, to do the fractional distillation, cutting α-pinene, make camphene through isomerization, and then obtain it by fractional distillation. The secondary product of camphene is dipentene. Additional,dipentene can be obtained when use turpentine is to do the hydratization to manufacture Terpineol.