A synthesis of conjugated dienes from aromatic, five-membered heterocycles
Abstract
Reaction of furan, thiophene, selenophene, and tellurophene as well as 2-methyl and 2,5-dimethyl derivatives of the first two heterocycles with phenyl-, methyl-, and n-butyl-magnesium bromides in the presence of ligated nickel dichloride are shown to yield buta-1,3-dienes mostly with retention of configuration.