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对O.Isler合成维生素A路线进行了工业化生产条件的考查,并对Darzene反应合成重要中间体十四碳醛的工艺条件做了改进,使总收率有了比较显著的提高。十四碳醛的合成,参考Stieg专利,并改为将甲醇钠甲醇溶液,经减压浓缩后,加入吡啶制成混悬液,冷至—25℃,将β-紫罗兰酮与氯乙酸甲酯混合物滴加入內。所得环氧酯用苛性钠甲醇溶液水解,省去了金属钠砂及粉末状甲醇钠的制备,收率尚可提高10％以
The industrialization conditions of O.Isler synthetic vitamin A route were investigated, and the process conditions for the synthesis of fourteen carbon aldehyde, an important intermediate of Darzene reaction, were improved. The total yield has been significantly improved. For the synthesis of tetradecaraldehyde, reference is made to Stieg’s patent, and instead sodium methoxide methanol solution was concentrated under reduced pressure and added with pyridine to make a suspension. The mixture was cooled to -25 ° C and β-ionone was reacted with methyl chloroacetate The mixture was added dropwise. The resulting epoxy ester hydrolyzed with caustic soda methanol solution, eliminating the need for the preparation of metallic sodium sand and powdered sodium methoxide, the yield can still be increased by 10%