Transcript 1 Carboxylic Acids GOB Structures

Lecture Presentation
Chapter 16
Carboxylic Acids
and Esters
Karen C. Timberlake
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
Chapter 16 Carboxylic Acids and Esters
Surgical technicians prepare the
operating room and the patients
for surgery by
• creating a sterile environment
in the surgical room.
• washing, shaving, and
disinfecting incision sites.
During the surgery, a surgical
technician provides the sterile
instruments and supplies to the
surgeons and surgical
assistants.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
Chapter 16 Readiness
Core Chemistry Skills
• Writing Equations for Reactions of Acids and
Bases (11.7)
• Naming and Drawing Alkanes (12.2)
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
16.1 Carboxylic Acids
A carboxylic acid contains a carboxyl group, which consists of
a hydroxyl group —OH attached to the carbon in a carbonyl
group.
Learning Goal Write the IUPAC and common names for
carboxylic acids, and draw their condensed and line-angle
structural formulas.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
IUPAC Names for Carboxylic Acids
In the IUPAC names of carboxylic acids,
• the e in the alkane name is replaced with oic acid.
CH4
Methane
Methanoic acid
CH3—CH3
Ethane
Ethanoic acid
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
IUPAC Names for Carboxylic Acids
Substituents are numbered from the carboxyl, which is
carbon 1.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
IUPAC Names for Carboxylic Acids
• As before, for benzoic acid, the placement of substituents is
shown using the prefixes ortho, meta, and para.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
IUPAC Names for Carboxylic Acids
Many carboxylic acids are still named by their common names,
which use prefixes: form, acet, propion, butyr.
• When using the common names, the Greek letters alpha (α),
beta (β), and gamma (γ) are assigned to the carbons
adjacent to the carboxyl carbon.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
Common Carboxylic Acids
A red ant sting contains
methanoic acid (formic acid)
that irritates the skin.
The sour taste of vinegar is
due to ethanoic acid (acetic
acid).
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
Guide to Naming Carboxylic Acids
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
Naming Carboxylic Acids
Give the IUPAC and common name for the following
carboxylic acid:
ANALYZE
THE
PROBLEM
Given
carboxylic acid
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
Need
IUPAC and
common name
© 2016 Pearson Education, Inc.
Naming Carboxylic Acids
Give the IUPAC and common name for the following
carboxylic acid:
STEP 1 Identify the longest carbon chain and replace
the e in the alkane name with oic acid.
The IUPAC name for a carboxylic acid with three
carbons is propanoic acid. The common name is
propionic acid.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
Naming Carboxylic Acids
Give the IUPAC and common name for the following
carboxylic acid:
STEP 2 Name and number any substituents by
counting the carboxyl group as carbon 1.
IUPAC name
Common name
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
2-methylpropanoic acid
2-methylpropionic acid
© 2016 Pearson Education, Inc.
Study Check
Give the IUPAC name of each compound.
A.
B.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
Solution
Give the IUPAC name of each compound.
A.
3-hydroxypentanoic acid
B.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
3-bromobenzoic acid
© 2016 Pearson Education, Inc.
Study Check
Draw the line-angle structure for
4-chlorohexanoic acid.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
Solution
Draw the line-angle structure for
4-chlorohexanoic acid.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
Preparation of Carboxylic Acids
Carboxylic acids
• can be prepared from primary alcohols or aldehydes.
• can be produced from the oxidation of primary alcohols to
aldehydes and then to carboxylic acids.
Ethanol in wine is oxidized by oxygen in the air, converting the
primary alcohol to acetaldehyde and then to acetic acid, the
carboxylic acid in vinegar.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
Chemistry Link to Health:
Alpha Hydroxy Acids
Alpha hydroxy acids (AHAs)
• are found in fruits, milk, and sugar cane.
• are naturally occurring carboxylic acids with a hydroxyl
group on the carbon atom that is adjacent to the
carboxyl group.
Dermatologists have been using products with high
concentrations (20–70%) of AHAs to remove acne scars and
in skin peels to reduce irregular pigmentation and age spots.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.
Chemistry Link to Health:
Alpha Hydroxy Acids
Several different alpha hydroxy acids may be found in skin
care products singly or in combination.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake
© 2016 Pearson Education, Inc.