Tandem Semipinacol Rearrangement Reaction Toward The Construction Of Furan And Spirocyclo[4.5]Decane Architecture

Semipinacol rearrangement reaction is a powerful synthesis tool with unique characteristics,which can realize the construction of complex molecular structures,particularly the quaternary carbon stereocenters,through the migration of atom or group and reorganization of chemical bonds,and increase the complexity and diversity of molecular structure.Our research group has been committed to the study on the tandem semipinacol rearrangement reaction and the application in the total synthesis of natural products for past decades.In this dissertation,we mainly carried out two tpyes of synthethic methods based on the tandem semipinacol rearrangement reaction as a continuing research direction of our group,realized the construction of furan motifs and spirocyclo[4.5]decane architecture,respectively.Then we applied this synthetic method to the synthesis of related natural products successfully.This dissertation contains the following three chapters: 1)the summary of research progress on furan compounds and the study of ?-alcohols radical addition/semipinacol rearrangement reaction leading to furans;2)the overview of the research on spirocyclo[4.5]decane structure;3)the study of tandem Castro-Stephens coupling/acyloxy shift/cyclization/semipinacol rearrangement sequence.In chapter one,we reviewed the preparation of furan compounds according to the reaction types.Then we developed a formal [3 + 2] cycloaddition through a free radical addition/semipinacol rearrangement reaction of simple alcohols with diaryl allyllic alcohols.A series of furan and dihydrofuran were prepared efficiently.In chapter two,we summarized the synthetic methods of all carbon spirocyclo[4.5]decane,mainly discussed the possible mechanism and the synthetic application in natural products.In chapter three,we carried out the research on the preparation of multiple reactive site and highly functionalized spiro bicycles containing quaternary carbon through a Castro-Stephens coupling/acyloxy shift/cyclization/semipinacol rearrangement sequence of propargyl ester and allyl bromide.Based on this synthetic method,we have completed the total synthesis of sesquiterpene erythrodiene and spirojatamol,explored the synthesis of intermediates of diterpene conidiogenone,and realized the construction of the key fused 6/5/5/5 tetracyclic skeleton of waihoensene.