Metal Free Synthesis Of Pharmaceutical Intermediate β-Ionone Epoxide Catalyzed By Se/C

The epoxide of β-ionone is widely applied in hormone synthesis and is a key intermediate in pharmaceutical synthesis.Therefore,developing the metal-free synthetic techniques of this compound to avoid the metal residue in product is of good practical values.On the other hand,selenium chemistry investigation is unfolding.Selenium is a bio-compatible element and its price is cheap,and the selenium resources in China are very rich.Therefore,it is of great strategic value to make full use of selenium resources and give full scope to its resource advantages.In this thesis,a series of heterogeneous selenium catalysts(Se/C)were designed and prepared to catalyze the selective epoxidation reaction ofβ-ionone and the oxidation of β-carotene to prepare the β-ionone starting material,affording a metal-free synthetic technique for the production of the epoxide of β-ionone.The detailed results are as follows:Firstly,we prepared a series of Se/C materials by using glucose as carbon source with different selenium content,and evaluated their performances in the epoxidation reaction ofβ-ionone.The effects of solvent,catalyst dosage,oxidant,temperature and time on the reactions were investigated.Finally,the highly selective epoxidation of β-ionone was realized and gave 62%product yield.In addition,the carbon sources of the catalyst were expanded and the heterogeneous catalyst was successfully recycled and reused.Secondly,inspired by the previous part of the catalyst carbon source expansion research,we used cheap and easily available biomass wheat straw as the catalyst support to develop the selenized wheat straw as the catalyst for the oxidation of β-ionone.Compared with Se/C,the preparation of selenized straw is more convenient,and the price of wheat straw is much lower than that of glucose,so the cost of catalyst can be greatly reduced.Finally,we investigated the application of Se/C catalysis technology in the oxidative degradation of β-carotene to produce β-ionone.It was found that the Se/C catalyst being prepared with chitosan as carbon source was the most preferable catalyst,and the degradation of β-carotene could be achieved under aerobic conditions.The technique may be applied in polyele degradation,which is also a significant issue in pharmaceutical industry.