- Synthetic method of astaxanthin
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The invention provides a synthesis method of astaxanthin, and belongs to the technical field of pharmaceutical chemicals, a compound 21 and a compound 22 are firstly prepared, then the compound 21 and the compound 22 are used for synthesizing a compound 5, and then the compound 5 and a compound 6 are used for generating astaxanthin, raw materials are easy to obtain in the whole preparation process, the synthesis process is safe and easy to operate, and the product yield is high; the compound 21 is 4-halogenated-2-methyl-2-butene-1-methylal, the compound 22 is 2, 2, 4, 6, 6-pentamethyl-5, 6, 7, 7a-tetrahydro-5-methylene-1, 3-benzodioxolane, the compound 5 is 3-methyl-5-(2, 6, 6-trimethyl-3-oxo-4-hydroxy-1-cyclohexenyl)-2, 4-pentadienyl triphenyl phosphine halide, and the compound 6 is 2,7-dimethyl-2, 4, 6-octyl trienaraldehyde.
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- Method for synthesizing astaxanthin intermediate
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The invention relates to a method for synthesizing an astaxanthin intermediate. The method specifically comprises the following steps: 1) adding lithium into liquid ammonia to implement a reaction, introducing acetylene to synthesize acetylene-based lithium, replacing the liquid ammonia with an organic solvent, and adding 1-butene-3-ketone to implement a reaction continuously, so as to generate 3-methyl-1-amylene-4-alkyne-3-lithium alkoxide; 2) adding lithium into the liquid ammonia to implement a reaction, and further adding the product obtained in the step 1) to generate 3-methyl-1-amylene-4-alkynyl based lithium-3-lithium alkoxide; 3) performing a condensation reaction on the product obtained in the step 2) with heterogeneous diketone so as to generate a condensation compound; 4) performing acid hydrolysis on the condensation compound obtained in the step 3), and treating with a reduction triple bond so as to obtain 2,4,4-trimethyl-6-hydroxy-3-(3-methyl-1,4-dipentene-3-hydroxy)-2-cyclohexenone; 5) enabling 2,4,4-trimethyl-6-hydroxy-3-(3-methyl-1,4-dipentene-3-hydroxy)-2-cyclohexenone to react with hydrobromic acid and triphenylphosphine in sequence, thereby finally generating the astaxanthin intermediate. By adopting the method, multiple times of introduction and repeated hydrolysis of extra protection groups are avoided, so that the raw materials are saved, and the preparation route is simplified.
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- PROCESS FOR THE PREPARATION OF OXOVINYLIONOL AND ITS O-PROTECTED DERIVATIVES
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The present invention relates to the preparation of oxovinylionol and its O-protected derivatives of the formula I in which R is hydrogen or an OH protecting group, for example a group Si(Ra)3, by reacting a compound of the general formula II in which R has the meanings given above for formula I, i.e. β-vinyl ionol (formula II, R=hydrogen) or an O-protected derivative thereof (formula II, R═OH protecting group) with an oxidant in the presence of at least one transition metal, where the oxidant comprises at least one oxygen-containing compound which is selected from among hydrogen peroxide and organic hydroperoxides.
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