Metal-Ammonia Reduction. Part II. Space-Conjugated Olefins

Abstract

Whilst metal-alcohol-liquid ammonia conditions do not reduce isolated double bonds², the “space-conjugated”³ norbornadiene has been shown to reduce to norbonene⁴. This result has been interpreted as the consequence of the availability of a low energy antibonding orbital arising from the proximity interaction of the two double bonds. The “nonclassical radical anion” 1 has been proposed⁴ as the intermediate though no nortricyclene could be detected to support this suggestion. However nortricyclene was produced when lithium in ethylamine was used as the reducing agent.⁵