... In summary, the chemistry described above represents an interesting extension to the chemistry of iminium ions. Also, the dimerization of these compounds results in a uni- que class of heterocyclic compounds. ... 1717 (m, 8H), 2.9 (m, 4H), 5.8 (s, IH), 6.0 (e, IH), 6.05 (d, J = 1-2 ...