Aldehydes and Ketones

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Aldehydes and Ketones

• In an aldehyde, an H atom is attached to a
  carbonyl group
• O carbonyl group
• ?
• CH3-C-H
• In a ketone, two carbon groups are attached to a
  carbonyl group
• O carbonyl group
• ?
• CH3-C-CH3

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Naming Aldehydes

• IUPAC Replace the -e in the alkane name -al
• Common Add aldehyde to the prefixes form (1C),
  acet (2C), propion(3), and butry(4C)
• O O O
• ? ? ?
• H-C-H CH3-C-H CH3CH2C-H
• methanal ethanal propanal
• (formaldehyde) (acetaldehyde)
  (propionaldehyde)

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Aldehydes as Flavorings
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Glucose is an aldehyde
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Naming Ketones

• In the IUPAC name, the -e in the alkane name is
  replaced with -one
• In the common name, add the word ketone
• after naming the alkyl groups attached to the
  
• carbonyl group
• O O
• ? ?
• CH3 -C-CH3 CH3-C-CH2-CH3
• Propanone 2-Butanone
• (Dimethyl ketone) (Ethyl methyl ketone)

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Ketones

• O O
• ? ?
• Butter flavor CH3-C-C-CH3 butanedione
• O
• ?
• Clove flavor CH3-C-CH2CH2CH2CH2CH3
• 2-heptanone

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Fructose is a Ketone

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Ketones as Hormones
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Learning Check AK 1

• Classify each as an aldehyde (1), ketone (2) or
  neither(3).
• O
• ?
• A. CH3CH2CCH3 B. CH3-O-CH3
• CH3 O
• ?
• C. CH3-C-CH2CH D.
• CH3

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Solution AK 1

• Classify each as an aldehyde (1), ketone (2) or
  neither(3).
• O
• ?
• A. CH3CH2CCH3 2 B. CH3-O-CH3 3
• CH3 O
• ?
• C. CH3-C-CH2CH 1 D. 2
• CH3

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Learning Check AK 2

• Name the following
• O
• ?
• A. CH3CH2CCH3 B.
• O
• ?
• C. CH3-CH-CH2CH
• CH2CH3

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Solution AK 2

• O
• ?
• A. CH3CH2CCH3 B.
• 2-butanone (ethyl methyl ketone)
• O
• ?
• C. CH3-CH-CH2CH
• cyclohexanone
• CH2CH3
• 3-methylpentanal

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Learning Check AK 3

• Draw the structural formulas for each
• A. 4-Methylpentanal
• B. 2,3-Dichloropropanal
• C. 3-Methyl-2-butanone

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Solution AK 3

• Draw the structural formulas for each
• CH3 O
  ?
• A. 4-Methylpentanal CH3CHCHCH2CH
• Cl O
• ?
• B. 2,3-Dichloropropanal Cl-CH2CHCH
• 
  O
• ?
• C. 3-Methyl-2-butanone CH3CHCCH3
• CH3

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Carboxyl Group

• Carboxylic acids contain the carboxyl group on
  carbon 1.
• O
• ??
• CH3 COH CH3COOH
• carboxyl group

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Naming Carboxylic Acids

• Formula IUPAC Common
• alkan -oic acid prefix ic acid
• HCOOH methanoic acid formic acid
• CH3COOH ethanoic acid acetic acid
• CH3CH2COOH propanoic acid propionic acid
• CH3CH2CH2COOH butanoic acid butyric acid

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Naming Rules

• Identify longest chain
• (IUPAC) Number carboxyl carbon as 1
• (Common) Assign ?, ?, ? to carbon atoms adjacent
  to carboxyl carbon
• CH3
• CH3 CHCH2 COOH
• IUPAC 3-methylbutanoic acid
• Common ?-methylbutryic acid

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Learning Check CA1

• Give IUPAC and common names
• A. CH3COOH
• CH3
• CHCOOH
• CH3

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Solution CA 1

• A. CH3COOH
• ethanoic acid acetic acid
• CH3
• B. CH3CHCOOH
• 2-methylpropanoic acid
• ?-methylpropionic acid

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Properties

• Carboxylic acids are weak acids
• CH3COOH H2O CH3COO H3O
• Neutralized by a base
• CH3COOH NaOH CH3COO Na H2O

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Esters

• In and ester, the H in the carboxyl group is
  replaced with an alkyl group
• O
• ??
• CH3 CO CH3 CH3COO CH3
• ester group

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Esters in Plants

• Esters give flowers and fruits their pleasant
  fragances and flavors.

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Naming Esters

• Name the alkyl from the alcohol O-
• Name the acid with the CO with ate
• acid alcohol
• O
• ?? methyl
• CH3 CO CH3
• Ethanoate methyl ethanoate (IUPAC)
• (acetate) methyl acetate (common)

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Some Esters and Their Names

• Flavor/Odor
• Raspberries
• HCOOCH2CH3 ethyl methanoate (IUPAC)
• ethyl formate (common)
• Pineapples
• CH3CH2CH2 COOCH2CH3
• ethyl butanoate (IUPAC)
• ethyl butyrate (common)

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Learning Check CA 2

• Give the IUPAC and common names of the following
  compound, which is responsible for the flavor and
  odor of pears.
• O
• ??
• CH3 CO CH2CH2CH3

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Solution CA2

• O
• ?? propyl
• CH3 CO CH2CH2CH3
• propyl ethanoate (IUPAC)
• propyl acetate (common)

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Learning Check CA 3

• Draw the structure of the following compounds
• 3-bromobutanoic acid
• Ethyl propionoate

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Solution CA 3

• A. 3-bromobutanoic acid
• Br
• CH3CHCH2COOH
• B. Ethyl propionoate
• O
• ??
• CH3 CH2 COCH2CH3 CH3CH2COOCH2CH3

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Esterification

• Reaction of a carboxylic acid and alcohol
• Acid catalyst
• O
• ?? H
• CH3 COH HOCH2CH3
• O
• ??
• CH3 COCH2CH3 H2O

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Hydrolysis

• Esters react with water and acid catalyst
• Split into carboxylic acid and alcohol
• O
• ?? H
• H COCH2CH3 H2O
• O
• ??
• H COH HOCH2CH3

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Saponification

• Esters react with a bases
• Produce the salt of the carboxylic acid and
  alcohol
• O
• ??
• CH3COCH2CH3 NaOH
• O
• ??
• CH3CO Na HOCH2CH3
• salt of carboxylic acid

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Learning Check CA4

• Write the equation for the reaction of propionic
  acid and methyl alcohol in the presence of an
  acid catalyst.

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Solution CA4

• O
• ?? H
• CH3CH2COH HOCH3
• O
• ??
• CH3CH2COCH3 H2O

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Learning Check CA5

• What are the organic products when methylacetate
  reacts with
• A. Water and an acid catalyst?
• B. KOH?

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Solution CA5

• A.
• O
• ??
• CH3COH HOCH3
• O
• ??
• B. CH3CO K HOCH3