[bobo]

The diels alder reaction between a cis diene and maleic anhydride should proceed at elevated temperatures. But how about a trans?

I assume, cis-trans isomerisation will occur from a certain temperature upwards. Then, the equilibrium will be dragged because the MA reacts with the cis compound. In theory. In practice, I tried both nitrobenzene as solvent as well as MA itself, neither produced anything in good yield. Things end up as blackened tar. Does anyone have an idea which conditions to use for this reaction?