Chapter 12, Problem 42P

Evaluate each of the following processes applied to cyclononatetraene, and decide whether

the species formed is aromatic or not.

Addition of one more π electron, to give ${\text{C}}_9{\text{H}}_{10}{}^{-}$

Addition of two more π electrons, to give ${\text{C}}_9{\text{H}}_{10}{}^{2^{-}}$

Loss of H+ from the ${\text{sp}}^{\text{3}}$-hybridized carbon

Loss of H+ from one of the ${\text{sp}}^{\text{2}}$-hybridized carbons