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Copyright © 2017 Pearson Education, Inc.
CHAPTER 8
Delocalized Electrons: Their Effect on Stability, p
K
a
, and the Products of a Reaction • Aromaticity and
Electronic Effects: An Introduction to the Reactions of Benzene
Important Terms
1,2-addition
addition to the 1- and 2-positions of a conjugated system.
(direct addition)
1,4-addition
addition to the 1- and 4-positions of a conjugated system.
(conjugate addition)
aliphatic compound
an organic compound that does not contain an aromatic ring.
allene
a compound with two adjacent double bonds.
allylic carbon
a carbon adjacent to an
sp
2
carbon of a carbon–carbon double bond.
allylic cation
a compound with a positive charge on an allylic carbon.
antiaromatic compound
a cyclic and planar compound with an uninterrupted cloud of
p
electrons contain-
ing an even number of pairs of
p
electrons.
antibonding molecular
the molecular orbital formed when out-of-phase orbitals interact.
orbital
antisymmetric molecular
a molecular orbital that does not have a plane of symmetry but would have one if half
orbital
of the MO is turned upside down.
aromatic compound
a cyclic and planar compound with an uninterrupted cloud of
p
electrons contain-
ing an odd number of pairs of
p
electrons.
benzylic carbon
a carbon, joined to other atoms by single bonds, that is bonded to a benzene ring.
benzylic cation
a compound with a positive charge on a benzylic carbon.
bonding molecular orbital
the molecular orbital formed when in-phase orbitals overlap.
bridged bicyclic compound
a bicyclic compound in which the rings share two nonadjacent carbons.
common intermediate
an intermediate that reaction pathways have in common.
concerted reaction
a reaction in which all the bond-making and breaking processes occur in a
single step.
conjugate addition
addition to the 1- and 4-positions of a conjugated system.
conjugated diene
a compound with two conjugated double bonds.
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