[TerrifiedPreMed]

Hello all,
I'm doing a research product on the efficacy of different lewis-acids to catalyze diels-alder reactions. I want to measure the rate of product formation through UV-Vis sprectoscopy, but I need a reaction in which the product of the reaction is colored, while the products are not. I've been scouring Google Scholars to no avail 


Any ideas for substrates?

[Babcock_Hall]

Draw out a typical Diels-Alder reaction, and let's examine it.

[TerrifiedPreMed]

Typically a Diels Alder is a reaction between a conjugated diene and a substituted alkene (dienophile) to form a substituted cyclohexane.

I've attached an image sketching out the reaction.

The Lewis Acid catalyzes the reaction by coordinating with the Dienophile to make it more reactive. This works really well if there is a carbonyl oxygen on the dienophile.

I could forgo using UV vis spectroscopy, which would allow me to use substrates that are less reactive in solution (and thus really only give me a decent yield with the addition of acid), but in that case I need to find a different way to isolate the product/measure the rate of the reaction.

[Babcock_Hall]

The product is a cyclohexene, not a cyclohexane (your title confused me initially).  Now compare the diene to the product.  Will one absorb UV light at longer wavelength?  Why?