Synthesis of β‐Truxinate via [2+2] Cycloaddition of Methyl 4‐Nitrocinnamate: Kinetic Study of its Isomerization with DBU.

This work concerns the isomerization of the product obtained by dimerization of methyl 4‐nitrocinnamate. Subsequent isomerization was performed using 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) as a base to obtain the corresponding ζ‐ and δ‐truxinate derivatives. The process was monitored by 1 H NMR spectroscopy in different deuterated solvents with a wide range of dielectric constants, acetonitrile‐ d 3 , acetone‐ d 6 , tetrahydrofuran‐ d 8 , and benzene‐ d 6 . Each solvent was found to have a distinct influence on the reaction's rate constant k , with acetone‐ d 6 yielding the highest ratio of ζ‐truxinate derivative. Kinetic analysis of the reaction provided valuable information about the mechanism involved in the isomerization process.