Studies On The Organic Synthesis Reactions Catalyzed By Solid Acids & Structural Analysis

This thesis consists of three chapters.In the first chapter, H2NSO3H is found to be an efficient catalyst. Because of its acidity, inexpensive, noncorrosive and nonpollution, H2NSO3H has been extensively used in a variety of organic reactions. An efficient and convenient method for the preparation of 1,1-diacetatesfrom aldehydes catalyzed by H2NSO3H under supersonic has been presented. The present method is better than conventional counterparts because it has such merits as short reaction time, high yield and easy to control. What must be mentioned is that aldehyde was selectively protected when ketone was present in the reaction.In the second chapter, H2NSO3H was used to catalyst the deprotection of 1,1-diacetates. In this reaction 1,1-diacetates transformed into corresponding aldehydes in good to high yield. In convenient method, the reaction was catalyst by H2SO4 or HC1, but the two catalysts both have their drawbacks such as corrosion, effluent pollution, non-recoverable and low yields. We mainly studied the procedure for deprotection of 1,1-diacetates catalyzed by H2NSO3H under microwave irradiation or through conventional method. As a result, both methods have the merits of short reaction time, high yields and easy to control.In the third chapter, a rapid and efficient method for the transdithioacetalization of 1,1-diacetates with 1 ,2-dithioglycol was described in good to excellent yield catalyzed by POCl3-montimorillontie. In the literature the dithiolanes was prepared mainly from aldehydes, ketone or acetals, so we had developed a new method to synthesis the dithiolanes. This method has the advantages of high yields, recoverable catalyst and easy of set-up and work-up.