7-keto cholesteryl-9-carboxyl nonane and synthesis method of fluorescent marker thereof

The invention relates to 7-keto cholesteryl-9-carboxyl nonane and a synthesis method of a fluorescent marker thereof. Cholesterol and azelaic acid are used as raw materials, 1,3-dicyclohexyl carbodiimide and 4-dimethylamino pyridine are used as a catalyst for synthesis reaction, and dichloromethane is used as a solvent to establish an oxidation system, and finally the 7-keto cholesteryl-9-carboxyl nonane is obtained through fat reduction reaction. The synthesis method of the 7-keto cholesteryl-9-carboxyl nonane is simple and convenient to operate, the raw materials are easy to obtain, the impurity content is low, and the production cost is low. The invention further provides a synthesis method of NBD-fluorescent group introduced 7-keto cholesteryl-9-carboxyl nonane. NBD-fluorescent groups are introduced on the basis that a basic framework structure is ensured, and finally NBD-oxLig-1 is synthesized so that the 7-keto cholesteryl-9-carboxyl nonane (oxLig-1) can produce spontaneous fluorescence and is used for tracer application in cell biology.