Studies On The Applications Of α-Oxoketene Dithioacetals To The Synthesis Of Lactone

α-Oxoketene dithioacetals are a kind of versatile intermediates used in organic synthesis during the past century. Since Kelber first synthesized theα-benzoyl ketene-(S,S)-acetal in 1910,α-oxo ketene-(S,S)-acetals chemistry has become an important division in organic chemistry through the development of near one hundred years. Particular in recent three decades, quite amount of documents have been published in this area, and several reviews were successively reported to summarize these results. Generally, the reaction types involovingα-oxoketene-(S,S)-acetals mainly include the regioselective addition-aromatization withorganometallic reagents, conjugate addition-cyclization with nitrogen nucleophilicspecies, nucleophilic reactions ofα-carbon,acting as odorless dithiol equivalentsin thioacetalization, Michael additions and [5+1] annulation, as well as the synthetic applications based on the above reactions.Among the variousα-oxo ketene-(S,S)-acetals,α-acetyl ketene-(S,S)-acetals andα-alkenoyl ketene-(S,S)-acetals are easier to prepare and bear much more functionalities. We had have the extensive studies on their applications, The focus of these research is theα-functionalized reactions ofα-position, for example, bromination, nitration, acetylation. And have utilized Baylis-Hillman Reaction and intramolecularα-functionalized reactions to synthesize a series of Carbocyclic compound and Heterocyclic compound. For expand the application ofα-Oxoketene dithioacetals. We hope the new method will be attained by strengthen the polarization ? ofα-oxo ketene-(S,S)-acetals and make it react with ethyl 3-chloro-3-oxopropanoate.Development of new synthetic methods is the basis for the innovation and advance of organic chemistry. Based on the researchachievement of our group inα-oxo ketene-(S,S)-acetal chemistry in the past years, my thesis starts from the synthesis ofα-acetyl-α-carbamoyl ketene-(S,S)-acetals andα-alkenoyl ketene-(S,S)-acetals through synthetic design, aming to develop new synthetic methods for interesting cyclic molecules, particularly,developing a new synthetic strategy to provide a general and simple route to lactone.