http://csi.chemie.tu-darmstadt.de/ak/immel/tutorials/reactions/index2.html#dielsalder1
For me, it looks like the videos at this link no longer play inside Chrome or Safari browsers. :(
Let me know if you can get it to work. The way that I could do it is if I downloaded the file (by right clicking on “mpeg” underneath each image, then viewing it on my computer.
Here is a screen recording I made of one of the videos, playing on my computer: