Question

Photochemical isomerization of Alkene: cis-1,2-dibenzoylethylene

6-38: What are some clues that tell you that you have made a different isomer product in this reaction?

6-39: Suggest a reason why the starting material (trans-1,4-diphenyl-2-butene-1,4-dione) should be recrystallized(or pure) prior to use ( NOTE: you did not perform the recrystallization, but were provided with the recrystallized material).

6-40:Cis-and trans-1,4-diphenyl-2-butene-1,4-dione are stereoisomers. What is the specific relationsip between the two of them?

6-41:Explain how this photochemical isomerizartion allows the production of the thermodynamically less stable cis isomer. In other words, why is the trans isomer exclusively converted to the cis isomer during short reaction periods and not vice versa? is it possible, under these conditions, that the trans and cis isomers are in rquilibrium with one another?

Answer 1