Construction Of ?-tetralone Structure And Synthesis Of Viridin By Relay Reaction Of Carbon Radical To Vinyl Azide

C-H bond is the most basic unit structure in organic compounds.The direct functionalization of C-H bond can greatly shorten the synthesis steps,improve the synthesis efficiency,and has the characteristics of step economy,atomic economy and environmental friendliness.It has become a very active direction in the field of organic synthesis in recent years.As a complementary strategy for transition metal-catalyzed C-H bond activation,the radical induced remote hydrogen transfer(HAT)process enables site-selective direct functionalization of different types of inert C(sp³)-H bonds.The direct functionalization of C(sp³)-H bond is of great significance in the construction of lead skeleton of active intermediates and the synthesis of compounds with diversity or with drug potential.Vinyl azide is a special class of nitrogenous alkene compounds,which can be prepared by the reaction of terminal acetylene and TMSN₃.As a kind of synthetic blocks with diverse reactivity,vinyl azide compounds are widely used in the preparation of various nitrogenous compounds.We used vinyl azide as the precursor and mainly did the following two parts of the work.Chapter 1:In this paper,we develop a novel synthesis method for accurate activation of the remote C(sp³)-H bond via 1,5-HAT process.A series of?-tetrahydronaphthone compounds were synthesized by using vinyl azide as the precursor,sodium persulfate as the oxidant and 4-alkyl substituted Hantzsch ester as the alkylation reagent.The reaction has the following characteristics:(1)excellent stereoselectivity;(2)The reaction is simple and the conditions are mild;(3)Good substrate universality and functional group tolerance.Chapter 2:On the basis of the first part of the research,we completed the construction of the basic four-ring skeleton of Viridin,a natural product of furan steroid.The key intermediate of Viridin,a natural product of furan steroid with high chiral substitution,was synthesized from D-mannose by using asymmetric control strategy of substrate synthesis.