Synthesis of 1,4,5,6-tetrachloro-7,7-dimethoxybicyclo[2.2.1]hepta-2,5-dienylmethyl esters of p-substituted benzoic acids

The possibility of preparing 1,4,5,6-tetrachloro-7,7-dimethoxybicyclo[2.2.1]hepta-2,5-dienyl-methyl esters of p -substituted benzoic acids by [4+2]cycloaddition of tetrachlorodimethoxycyclo-pentadine to propargyl esters of the corresponding acids was examined. The optimal synthesis conditions were found. The structure of the compounds synthesized was confirmed by independent synthesis and by IR and 1 H NMR spectroscopy.