Solutions for Chapter 17: Conjugated Pi Systems and Pericyclic Reactions

A substance that yields hydrogen ions (H1) when dissolved in water. (2.7)

The species temporarily formed by the reactant molecules as a result of the collision before they form the product. (13.4)

Next to a carbon-carbon double bond.

A compound containing a carboxyl, !COOH, group.

In gas chromatography, a plot that identifies the retention time of each compound in the mixture.

The circulation of electron density in the presence of an external magnetic field, which produces a local (induced) magnetic field that opposes the external magnetic field.

An ionic compound that is formed upon treatment of a primary amine with NaNO2 and HCl.

A compound containing two hydroxyl groups (OH).

Theresulting net attraction between two dipoles.

Hydrogens that have the same chemical environment

Vibrations in the region 1500 to 400 cm21 of an IR spectrum are complex and diffi cult to analyze but are characteristic for different molecules.

A lithium dialkyl cuprate (R2CuLi).

A compound with hydroxyl (!OH) groups on adjacent carbons.

Atoms or groups on an atom that give an achiral molecule when one of the groups is replaced by another group. The hydrogens of the CH2 group of propane, for example, are homotopic. Replacing either one of them with deuterium gives 2-deuteropropane, which is achiral. Homotopic groups have identical chemical shifts under all conditions

A magneticfield generated by a spinning proton.

Elements in the s and p blocks of the periodic table. (Section 6.9)

A C6H5 group.

The branch of science that studies the interaction of matter and radiation.

The reverse of a Diels-Alder reaction, achieved at high temperature. A cyclohexene derivative is converted into a diene and a dienophile.

An applied magnetic fi eld causes the p electrons of an aromatic ring to circulate, giving rise to the so-called ring current and an associated magnetic fi eld that opposes the applied fi eld in the middle of the ring but reinforces the applied fi eld on the outside of the ring.