Rathane is a three-mushroom compound with thirty carbon atoms. At present, its preparation method has two kinds of semi-synthesis and total synthesis. The semi-synthetic method is the industrial production of cartonene, for example, by extracting cartonene from the livers of deep-sea-caught cartilage and then re-hydrogenating it. The total synthesis methods are: (1) Japanese Kuraray method; (2) oxidative coupling method of dehydronerolidol; (3) dimerization of dehydronerolidol followed by dehydration and hydrogenation; (4) from orange Carrageenene is prepared from anthocyanin and then hydrogenated; (5) Caratonene is prepared from farnesene and then hydrogenated.
1. Semi-synthetic method:
The horned soft-shelled turtle (Panthelidae) lives in the deep seas of Spain, Angola, Taiwan and the Philippines. In the past, cartonene was industrially produced by hydrogenation of cartonene obtained from turtle liver oil. This horned squid can only be caught in special fish farms in the deep sea of about 1,000 meters. It is very difficult to suppress its catch to meet the needs of caratane production.
2. Kuraray full synthesis method:
Japan Kuraray Co., Ltd. is a company specializing in the development of isoprene series of fine chemical products. In 1970, the company developed the technology for the total synthesis of cartonane from isoprene. In 1976, Kuraray Co., Ltd. built a production plant for mushroomene compounds in Niigata Prefecture’s Nakajo-Dei Natural Gas-to-Acetylene Plant. In 1977, the company began to sell carotene, which is synthesized from isoprene and synthesized from linalool. In the same year, the company also plans to build 1,000 tons/year hornbecene and 500 tons/year isophytol plant. According to recent Japanese data reports, the annual production capacity of the isoprene fully-synthesized serratane plant of Japan Kuraray Company is only a few hundred tons.
Synthesis process steps:
①Addition of isoprene and hydrogen chloride to obtain methylbutene chloride.
②Methylbutene chloride is condensed with acetone to obtain methylheptenone, and the catalyst is quaternary ammonium salt or phosphorus salt-sodium hydroxide solution.
③ methylheptenone is alkylated to obtain dehydrolinalool, and the catalyst is alkali-liquid ammonia.
④ Dehydrolinalool is hydrogenated to obtain linalool.
⑤ Linalool is condensed with ethyl phenol acetate to obtain geranyl acetone, and the catalyst is isopropyl aluminum-triethylamine
⑥Geranyl acetone is coupled with diacetylene to obtain diacetylene glycol, the catalyst is potassium hydroxide-liquid ammonia, and the reaction temperature is 15 ℃.
7. Diacetylenic diol is hydrogenated to obtain saturated diol, which is carried out in three steps. First, the unsaturated triple bond and part of the double bond of diacetylenic diol are hydrogenated by using Raney nickel catalyst. The solvent is hexane, and the reaction temperature is 100 ° C. , hydrogen partial pressure 15-20 kilograms/cm 2; Secondly, reclaim saturated diol with rectification; Finally: adopt Ni/Si-Al catalyst, make saturated diol hydrogenation.
⑧ Dehydration and hydrogenation of saturated diol to obtain squalane. Dehydration catalyst can use sulfuric acid, phosphoric acid, Lewis acid (zinc chloride, aluminum chloride), alumina, silica-alumina and solid phosphoric acid, etc.; hydrogenation catalyst can use Pd/c, Raney nickel, etc.
At present, Kuraray Company of Japan has built the world’s first isoprene fully synthetic serratane plant. The Kuraray total synthesis method has the following advantages: (1) not only can produce cartonane, but also can co-produce other mushroom ene compounds; (2) use N-methyl pyrrolidone to selectively absorb butadiyne (natural gas cracking to produce acetylene) (3) continuous synthesis of methyl heptene ketone; (4) the product has high purity and stable quality.