Arrange the following dienes in decreasing order of their relative reactivity towards dimethyl maleate (dimethyl cis -butenedioate) in a Diels-Alder reaction: (i) (ii) (iii)

Step-by-step solution

For a diene to undergo a Diels-Alder reaction, it must be able to adopt an s-cis conformation so that the ends of the diene can simultaneously interact with the dienophile. Let us analyze the given dienes based on their ability to adopt the s-cis conformation: 1. Diene (ii) - Cyclopentadiene: This molecule is a cyclic diene permanently locked in the s-cis conformation. Because no bond rotation is required and the ends of the diene are held at an optimal distance, it is exceptionally reactive towards dienophiles. Th