Of ¦Á-carbonyl Disulfide Reduction Enone Carbonyl Protection And Thiophene-ene And Its Analogues In The Synthesis

?-Oxo ketene dithioacetals, which carry polyfunctional groups, are a kind of versatile intermediates in organic synthesis and are widely studied in recent years. Protection and deprotection strategy are commonly used in the synthesis of natural products and complex compounds. Carbonyl group is one of the most important organic functional groups.So far thioacetalization is well-known as a reaction that protects carbonyl groups of aldehydes and/or ketones. The reagents of protecting carbonyl groups mostly are thiols. Though the reagents of thiols have lots of shortcomings: for example: flammable, expensive, harmful, obnoxious odor, inconvenient transportation and stocking etc, because of the thioacetalization reaction is very important in organic synthesis, tiols are still widely adopted as the reagents for protecting the carbonyl groups of aldehydes and/or ketones. Dithiine and its analogs are very important organic synthon, which are widely applied as precursors of bioactive compounds. At the present, these compounds are commonly prepared by using thiol as the starting materials. It is necessary to explore new kinds of reagents replacing thiols.Combining with the special properties of ?-oxo ketenedithioacetals, we have succeeded in exploring a new kind of reagents instead of thiols, moreover, which have been successfully applied on protecting the carbonyl groups of aldehydes and/or ketones and synthesis of dithiine and its analogs. These new reagents possess many merits, such as: stable, readily available, cheap, odorless and environment friendly etc. This work mainly based on the following two aspects:Firstly, we have successfully applied methyl 2-(1,3-dithian/dithiolan -2-ylidene) -3-oxobutanoate to protect the carbonyl groups of various aldehydes and/or ketones. Moreover, this method is simple, high yield, mild condition, fast and high chemoselective for aldehyde and ketone. Secondly, we have used 2-(1,3-dithian/dithiolan-2-ylidene) –3- oxobutanonic acid, methyl 2-(bis(benzylthio)methylene)-3- oxobutanoate , and 2-(bis(benzylthio)methylene)-3-oxobutanoic acid to synthesis a serials of dithiine and its analogs: 2,3-dihydro-1,4-dithiine, 6,7-dihydro-5H-1,4-dithiepine, 5,6,7,8- tetrahydro-1,4-dithiocine and their derivatives. These compounds are firstly obtained from no-thiol reagent and the method is simple, mild condition and environment friendly.In summary, we have succeeded in exploring a new kind of reagents instead of thiols, moreover, which have been successfully applied on protecting the carbonyl groups of aldehydes and/or ketones and synthesis of dithiine and its analogs. This method is simple, fast, high yield and mild condition. So these new reagents have good perspective in the field of basic research and practical applications.