| The special pharmacological effect of Vitamin K2 is paid more attention with the development of modern medicine, but its application and improvement are hindered by higher cost for its biological extraction. So it is being attached more and more importance that how to develop a chemical method to synthesize Vitamin K2 and put it into industrialization.The cognitive history, application field and physiological property of Vitamin K were summarized in this dissertation. The synthesis of Vitamin K2 by the intermediate of 1,4,4a,5,8,9a-hexahydro-9aα-memyl-1α,4α-methanoanthraquinone which was economical, fine stereoselectivity and fitting to industrialization was studied. Vitamin K2 can be synthesized in only three steps where cyclopentadiene was used as an auxiliary agent. When menadione reacted with cyclopentadiene in room temperature as initiative material, the molar yield of colorless crystal of endo-Diels-Alder additive product reached 92.4%. After that, Vitamin K2 can be obtained by alkylation from the former crystal with solanesyl bromide, and then retro-Diels-Alder reaction. The molar yield of these two steps were 85.3% based on 1,4,4a,5,8,9a-hexahydro-9aα-methyl--1α,4α-methanoanthraquinone, and the total molar yield is 78.8% based on menadione.The optimal conditions of synthesizing 1,4,4a,5,8,9a-hexahydro-9aα-methyl--1α,4α-methanoanthraquinone by Diels-Alder reaction were researched. The molar ratio of menadione and cyclopentadiene was 1:2, by which the amount of cyclopentadiene can be reduced. Tetrahydrofuran which can be removed by vacuum distillation easily was used as solvent, and then Retro-Diels-Alder reaction would be prevented effectively when in the distillation. Ferric chloride as catalyst made the cost relatively lower. Furthermore, the velocity and conversion of reaction can be balanced better as reacting in 10-15 ℃.1,4,4a,5,8,9a-hexahydro-9aα-rnethyl-4aα-[(2E,6E, 10E, 14 E, 1 8E,22'E,26E,30'E,--34 E)-3,7,11,15,19,23,27,31,35 ,-hexadecatetraenyl]-1 α,4α-methanoanthraquinonecan be obtained by the deprotonaton of I,4,4a,5,8,9a-hexahydro-9aa-methyl--la,4a-methanoanthraquinone with industrial sodium amide, and then alkylation with solanesyl bromide. The reaction velocity would speeded up effectively when 1,2-dimethoxyethane and N,N-dimethylfomamide as solvent with 9:1 of volume ratio. The reacting process was safe and cost was lower when industrial sodium amide was used as condensing agent. The problem of over low reacting temperature was settled down in -3 °C.The purity of product after treatment was higher and luster was fine when retro-Diels-Alder reaction of shorter duration was in 100°C for 40 minutes with toluene as solvent. The troublesome separation of column chromatography would be avoided as crude product recrystallized in n-butanol. The purity of product analyzed by HPLC was 98.1% and ratio of cis-form and trans-form was 9.1/91.9, which conformed to the criterion of pharmacopoeia.
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