Structural orientation in the diene condensations of isoprene with unsymmetrical dienophiles

Abstract

1. The diene condensations of isoprene with unsymmetrical dienophiles were investigated systematically. 2. Using the example of the diene condensation of isoprene with methyl acrylate at different temperatures, it was shown that the amount of meta somer in the mixture of adducts formed increased with a rise in temperature. 3. On the example of diene condensations of isoprene with esters of acrylic, methacrylic, and α-isopropylacrylic acids, it was shown that an increase in the volume of the substituent in the ce-position of the dienophile led to a fall in the meta isomer content of the adduct mixture. 4. Diene condensations of isoprene with acrylic acid and its methyl ester and nitrile and also with acrolein-formed mixtures of adducts with approximately the same ratio of structural isomers.