Lewis Acid Catalyzed Carbon−Carbon Bond Cleavage of Aryl Oxiranyl Diketones: Synthesis of <i>cis</i>-2,5-Disubstituted 1,3-Dioxolanes

Carbonyl ylide is one of the most important intermediates which can undergo a series of 1,3-dipolar cycloaddition reactions. The C−C heterolysis of oxirane is believed to be the most atom-economic and straightforward way to generate carbonyl ylide. However, this chemistry was only achieved under photochemical and thermal conditions in past years. In this work, the one-step diastereoselective synthesis of cis-2,5-disubstituted 1,3-dioxolanes via [3 + 2] cycloadditions of aldehydes and carbonyl ylide, which is obtained from Lewis acid catalyzed C−C bond heterolysis of aryl oxiranyl diketones at ambient temperature, is described.羰基叶立德（Carbonyl ylide）是一类至关重要的中间体，可参与一系列1,3-偶极环加成（1,3-dipolar cycloaddition）反应。环氧乙烷（oxirane）的C-C键异裂被公认为是生成羰基叶立德最具原子经济性且最为直接的途径。然而过往多年间，该类反应仅能在光化学与热化学条件下实现。本工作报道了一种室温下的合成策略：通过路易斯酸（Lewis acid）催化芳基环氧乙烷基二酮的C-C键异裂得到羰基叶立德，随后使其与醛类发生[3+2]环加成反应，一步完成顺式-2,5-二取代1,3-二氧戊环（cis-2,5-disubstituted 1,3-dioxolanes）的非对映选择性合成。