Chapter 19, Problem 71AE

(a)

Interpretation Introduction

Interpretation:

The eight structures for the given molecular formula, ${\text{C}}_{\text{5}}{\text{H}}_{\text{11}}\text{OH}$ has to be drawn and the IUPAC names for the corresponding structures has to be given.

Concept Introduction:

Alcohols:

Alcohols are organic compounds whose molecules contains the hydroxyl $\left(-\text{OH}\right)$ functional group bonded to ${\text{sp}}^3$ hybridized carbon. The general formula of alkyl halides is represented as follows:

IUPAC rules for naming alcohols:

• Identify the parent carbon chain in the given compound that must contain the hydroxyl functional group. If two or more chains have the same carbon lengths, choose the chain with a greater number of substituents bonded to it.
• The alcohol IUPAC name is derived from the respective alkane. Thus, the parent compound name is derived by replacing the $\text{-}e$ ending of the alkane to $\text{-}ol$. If two or more structural isomers are possible, use the position number for the hydroxyl group.
• The parent carbon chain is always numbered from the end of the chain only if the hydroxyl group has the lowest possible locant.
• Identify and name the alkyl groups including their positions on the parent carbon chain.
• If the parent carbon chain contains two or more same kinds of alkyl groups, indicate this repetition by a numerical multiplier ($di\text{-}$, $tri\text{-}$ and so on) used before the alkyl-group name. The numbers for alkyl group positions are separated by a comma and the alkyl-group name and the position number is separated by a hyphen.
• If the parent carbon chain contains several different alkyl groups, arrange them in alphabetical order (do not consider numerical multipliers). Write all alkyl group names that include their locants in front of the parent compound’s name.

(b)

Interpretation Introduction

Interpretation:

The eight open-chain structures identified in part (a) for the given molecular formula has to be classified as primary alcohols, secondary alcohols and tertiary alcohols.

Concept Introduction:

Alcohols are classified into three major types: primary alcohols, secondary alchols and tertiary alcohols.

Primary alcohols:

The carbon atom containing the hydroxyl group has one alkyl group and two hydrogens on it. The general structure for primary alchols is shown below:

Secondary alcohols:

The carbon atom containing the hydroxyl group has two alkyl groups and one hydrogen atom on it. The general structure for secondary alchols is shown below:

Tertiary alcohols:

The carbon atom containing the hydroxyl group has three alkyl groups and no hydrogens on it. The general structure for tertiary alchols is shown below: