The Aldol Reaction Of The Silyl Enol Ether Of Methyl Tetrahydrofuran-2-Carboxylate With Aldehyde Catalyzed By LiCl

With the rapid development of modern society in the field of organic chemistry, making organosilicon reagents of silyl enol ether is becoming a very important kind of organic synthetic intermediates, and has been widely used in the field of natural product synthesis. The silyl enol ether can be used in the synthesis of various a-alkyl ketones,β-hydroxy ketones or esters and α,β-unsaturated ketones. Even in the field of total synthesis, it is the important precursor for bioactive molecules (such as prostaglandins and steroid hormones). In the field of organic chemistry, the discovery of the Aldol reaction has the great significance. The addition of the silyl enol ether to aldehydes is the common and effective way to synthesize the β-hydroxy ketone or ester. In previous works the direct addition of ketone or ester to aldehydes was used to get the β-hydroxy ketone or ester. However, some nucleophiles such as oxygen-containing heterocyclic compounds are tough reagents for the Aldol reaction with quite low yield. The advancement appeared in recent years due to the rise of lewis acid catalysis in the addition of silyl enol ether to aldehydes. It has currently become a hot spot research because it greatly increased a number of Aldol reactions.In our study, we tried to use Lewis acid LiCl to catalyse the aldol reaction of the silyl ether of methyl tetrahydrofuran-2-carboxylate with aldehydes, after optimization of reaction conditions, we found that in the catalysis of LiCl the Aldol addition of the Silyl enol ether of methyl tetrahydrofuran-2-carboxylate to the aldehyde couild be performed in high yield. The highest yield was up to92%. Furthermore, the substrate scope is extensive in this study. In addition, the reaction system could be conducted in the relatively mild conditions. The operation is easy.