No this is not a recent scientific breakthrough, this is just one of those reactions that all people should know. It is a simple single step, yes you read correctly, single step Reaction that leads to the formation of a six membered ring. You may be wondering why is this an important reaction. Six membered rings are incredibly stable due to their low angle strain and great molecular orbital overlap and are all around us. All the reaction needs is a diene and a dienophile for this to occur and very little energy. These reactions form compounds that people take for granted. If you would like to test this experiment out for yourself it can be done very simply. All you need is some 3-sulfolene, maleic anhydride and dry xylene for the reaction. A reflux is done under gentle heat and thats it, to make the reaction go to completion. You may want to make sure that the solid maleic anhydride melts before the reaction goes to far or it may not all react with the butadiene formed from the 3-sulfone under heat. Causing some problems with correct yield. Other than that it's a simple reaction you should all try. Also dont forget to filtrate the reaction at the end to collect your product.

-MF

For more information on this reaction go to:
http://en.wikipedia.org/wiki/Diels%E2%80%93Alder_reaction