Alkoxyl Radical Promoted Structural Modification Of Aliphatic Alcohols And Antifungal Activity Investigation

Alcohols are commonly found in forest-derived natural products,turpentine derivatives,pesticides and biomass-degrading fine chemicals.Traditionally for the utilization of aliphatic alcohols,they are often converted to halogenated hydrocarbons through the Appel reaction and then undergo a series of nucleophilic reactions with a two-electron process by the Grignard reaction.However,this type of strategy has many drawbacks:the danger of Grignard reagent preparation,instability and the site-blocking effect of the reaction,which seriously hinder its application in chemical synthesis.How to efficiently utilize hydroxyl functional groups to achieve molecular structural diversity through bond-breaking/bond-forming strategies is very attractive and challenging.It is also a very strategic task to structurally modify traditional forestry resources based on hydroxyl-rich forest-derived bulk chemicals to enrich the functionalities of forest-derived active compounds and enhance their biological activities for pest and disease control in agroforestry.This thesis on how to efficiently utilize hydroxyl functional groups and modify the structure of bulk forest-derived chemicals,mainly focused on the efficient construction of various complex and rare chemical scaffolds using alcohol compounds as precursors to achieve molecular structural diversity,and studied the antifungal activity of derivatives modified with de-complicating pinene and camphor.A strategy based on alkoxyl radical was developed to modify the structure of alcohols.It was prepared as a stable alcohol derivative,N-alkoxyphthalimide,which formed a new C-C bond with glycine derivatives through free radical coupling process under visible light irradiation,and a variety of unnatural amino acid(UAA)and peptide derivatives were obtained.It was found that the reaction with 4Cz IPN as photosensitizer and DMSO as solvent was heated to 60 ~oC under blue LED for 5 hours,the corresponding product could be obtained with 92%yield.After substrate expansion and examining functional group compatibility,it is found that the strategy has a wide range of substrates and good compatibility with some biomolecules.The study of reaction mechanism proves that the reaction goes through the radical–radical coupling process,and the possible reaction mechanism is proposed.The antifungal activity of the modified derivatives ofβ-pinene and camphor was studied.The growth rate method was used to test the antifungal activity of six pathogenic fungi in vitro.(-)-β-pinene derived compound 28 and(+)-camphor derived compound 29 showed strong anti-fungus activity,respectively.Compound 29 showed strong anti-fungus activity against B.cinerea,S.,sclerotiorum,T.cucumeris and C.orbiculare,and the inhibition rate of compound 29 against S.sclerotiorum was as high as 75%.Compared with its parent compounds(β-pinene and camphor),the modified derivatives 28 and 29 achieved a breakthrough in the inhibition of bovines from zero to some,providing theoretical basis and experimental support for the later structural optimization.