The Study of Allylic Oxidation of Cholesterol-the Intermediate Product of Vitamin D3
|Keywords||Air oxidation Vitamin D3 Cholesterol 7 - one - cholesterol N-hydroxy- phthalimide|
The the vitamin D 3 < / sub > is the people and livestock, poultry growth , breeding, essential to sustain life and maintain a healthy fat-soluble vitamins . With the increasing aging of the population and the rapid development of animal husbandry , growing social demand for vitamin D 3 . Currently, the global part of the vitamin D 3 < / sub > of production bromide to eliminate , hydrolysis and UV irradiation process . Obviously , in the above - described process of bromine as an oxidizing agent extensive use inevitably , which brings bromine corrosion and bromine pollution equipment, the environment is not beneficial . At the same time , the byproducts are inevitable. Therefore, from the point of view of industry and environmental protection , there is an urgent need of a production of vitamin D 3 < / sub > 's no brominated green technology , it has also become academic focus in recent years . In this thesis, in order to the vitamin D 3 < / sub > key intermediates 7 - one - the synthesis of cholesterol as the research object , using molecular oxygen as the oxidant , from the point of view of environmental and economic design and development of a new process route . Allylic oxidation of N- hydroxy- phthalimide ( NHPI ) / transition metal salt catalyst system successfully applied to the cholesterol acetate . Mild reaction conditions, the process of environmental protection , and low production cost, high yield, can effectively replace the original route bromide , green production . In addition , we also discussed the NHPI catalytic oxidation process , the possible mechanism for cholesterol allylic oxidation . UV - visible spectroscopy by means of the key steps of the reaction mechanism and by electron spin resonance ( ESR ) combined with speculation and verification .