The previous post showed how the 2+2 cycloaddition of an alkene could occur by a sort of sideways insinuation of the bonds. I have also shown how the same reaction can occur with a dramatic rotation of one of the double bonds. This post compares the two moves side by side.
0.0 | 5.3 kcal/mol |
As is sometimes the case in real life, the forbidden option has the lower activation barrier!
Tags: pericyclic, Tutorial material