Study On α-Alkenoyl Ketene S, S-acetal-Based Multicomponent Reaction

Functionalized ketenedithioacetals are a kind of versatile intermediates in organic synthesis. Since Kelber first synthesized in 1910,α-oxo ketene-(S,S)-acetals chemistry has become a hot spot in organic chemistry research through the development of about one hundred years. It can be used in many reactions for their functional group multiplicity and special stereoelectronic effect from the alkylthio functionalities. It can construct many compounds with special structures and can be applied in organic synthesis and the composition of natural products.The carbon-carbon bond formation and the functional group transformations are most fundamental reactions for the construction of a molecular framework and hence represent a forefront of research in organic chemistry. Multicomponent reactions (MCRs) have been refined in recent years into powerful and useful tool in synthetic chemistry and attract increasing attention due to the fact that complex molecules and drugs can be prepared from cheap and easily available starting materials. This reaction covers simple operation, high resource utilization and high atom economy, etc. And it can be applied in the design, synthesis of new drugs, and compounds with special structures.In connection with the importance of carbon-carbon bond formation and multicomponent reactions, we will investigate the three components reaction ofα-alkenoyl ketene S,S-acetals, different aldehydes and active methylene compounds.My research includes the following five aspects:1,Explore the possibility of the three component reaction of readily availableα-alkenoyl ketene S,S-acetals with aldehydes and active methylene compounds to give various polyfunctionalized cyclohexanones.2,Variation of theα-Alkenoyl Ketene S,S-acetals, aldehydes and active methylene compounds in sequence.3,Application of polyfunctionalized cyclohexanones in the synthesis of unsymmetrical biaryls.4,Explore the optimization of the reaction conditions.5,Study the possible mechanism.Thirty-six new compounds were synthesized and characterized by IR, Mass and NMR (¹H, ¹³C) spectrum in this thesis.