Cyclopropane-1,2-dicarboxylic acid diethyl ester is primarily used as a versatile intermediate in organic synthesis. It is employed in the preparation of various cyclopropane derivatives, which are valuable in pharmaceutical research for developing bioactive compounds. The ester functional groups make it a useful precursor for further chemical modifications, such as hydrolysis, reduction, or transesterification. It is also utilized in the synthesis of complex molecules, including natural products and polymers, due to its ability to introduce cyclopropane rings into target structures. Additionally, this compound finds application in materials science, where it can be incorporated into the design of specialty chemicals and advanced materials.