Identify the compound that gives the mass spectrum and infrared spectrum shown here.
<IMAGE>

For each NMR spectrum, propose a structure consistent with the spectrum and the additional information provided.

<IMAGE>

a. Elemental analysis shows the molecular formula to be C₈H₇OCl. The IR spectrum shows a moderate absorption at 1602 cm^–1 and a strong absorption at 1690 cm^–1.

b. The mass spectrum shows a double molecular ion of ratio 1:1 at m/z 184 and 186.

<IMAGE>

An unknown compound gives the following mass, IR, and NMR spectra. Propose a structure, and show how it is consistent with the spectra. Show the fragmentations that give the prominent peaks at m/z 127 and 155 in the mass spectrum.

<IMAGES>

A student added 3-phenylpropanoic acid (PhCH₂CH₂COOH) to a molten salt consisting of a 1:1 mixture of NaCl and AlCl₃ maintained at 170 °C. After 5 minutes, he poured the molten mixture into water and extracted it into dichloromethane. Evaporation of the dichloromethane gave a 96% yield of the product whose spectra follow. The mass spectrum of the product shows a molecular ion at m/z 132. What is the product?

<IMAGE>

Why were no products from the McLafferty rearrangement observed in the spectrum of butan-2-one (Figure 18-3)?

<IMAGE>

Identify the peaks in the mass spectrum of octan-4-one that correspond to (b) the McLafferty rearrangement.

<IMAGE>

2-Methylnonan-4-one can undergo two different McLafferty rearrangements. Draw the products of each of them.

In the mass spectrum of the following compounds, which is the tallest—the peak at m/z = 57 or the peak at m/z = 71?

a. 3-methylpentane

b. 2-methylpentane

What hydrocarbons that contain a six-membered ring will have a molecular ion peak at m/z = 112?