ABSTRACT

An example for a general diene (the symbol E+ = electrophile, although the electrophile could be a radical):

b. The second step is addition of the nucleophile (Z:−) to the electrophilic carbon cation or radical generated in the first step. The new C Z bond is formed by transfer of the Z:− nucleophilic electrons to carbon. The result is formation of two new sigma bonds to the sp2 carbons at the expense of the original pi-bond between them.