Q53E Propose a structure consistent w... [FREE SOLUTION]

Chapter 17: Q53E (page 567)

Propose a structure consistent with the following spectral data for a
compound $C_{8} H_{18} O_{2}$ :
IR: $3350 {cm}^{- 1}$
${}^{1}H$ NMR: $1.56 未$ (12 H, singlet); $1.56 未$ (4 H, singlet); $1.95 未$ (2 H, singlet)

Short Answer

Expert verified

Alcohols comprise a strong C-O absorption peak near $1050 {cm}^{- 1}$ . A characteristic O-H stretching absorption is also seen in the range of 3300 to $3600 {cm}^{- 1}$ . The position of O-H stretch depends on the hydrogen bonding in that particular molecule.

Step by step solution

IR and H1 NMR spectrum of alcohols

Proposing the structure of the compound from the H1 NMR spectrum

The degree of unsaturation for the compound $C_{8} H_{18} O_{2}$ can be given as:

$Degree of unsaturation = \frac{2 C + 2 + N - H - X}{2} = \frac{2 脳 8 + 2 + 0 - 18 - 0}{2} = \frac{18 - 18}{2} = 0$

The compound has zero degree of unsaturation. Hence it has no double bonds or rings.

The IR band at $3350 {cm}^{- 1}$ indicates the presence of a hydroxyl group. The compound is symmetrical and has a simple NMR. The compound has four methyl groups connected to the carbon with no hydrogen on it. The compound also has two oxygen atoms. The two proton singlet atlocalid="1656406121537" $1.95 未$ can be assigned to two OH groups. The compound is a diol and the structure can be given as: