Chapter 15 Aldehydes, ketones

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Chapter 15Aldehydes, ketones
Aldehyde
Ketone

• Naming Ketones
• ID longest chain containing ketone
• Replace e with one
• e.g., propanone, butanone

• Naming Aldehydes
• ID longest chain containing aldehyde
• Replace e with al
• e.g., methanal, ethanal

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Physical Properties

• Boiling Points
• alkane lt ether lt aldehyde ? ketone lt alcohol
• Why?
• Solubility
• Aldehydes and ketones with less than 4 carbons
  are water soluble

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Reactions Oxidation
Remember Primary Alcohol ? Aldehyde ? Carboxylic
Acid

• Aldehydes
• Easily oxidized to carboxylic acid
• Tollens reagent Test for aldehyde

Question Can ketones be oxidized?
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Oxidation
Test for aldehydes which have OH alpha
(adjacent) to aldehyde
Hydroxyl
Aldehyde
Glucose
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Reduction (review)

• Aldehydes Reduced to primary alcohols
• Ketones Reduced to secondary alcohols

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Isomers Same formula, different structures

• Constitutional (structural) Isomers Isomers with
  different connectivity
• Stereoisomers Isomers with the same
  connectivity, but different spatial arrangement
• Enantiomers Non-superimposable mirror images of
  stereoisomers
• Diastereomers Stereoisomers that are NOT mirror
  images

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Constitutional (structural) Isomers Isomers with
different connectivity
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Stereoisomers Isomers with the same
connectivity, but different spatial arrangement

• Enantiomers Non-superimposable mirror images of
  stereoisomers

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Stereoisomers Isomers with the same
connectivity, but different spatial arrangement

• Diastereomers Stereoisomers that are NOT mirror
  images

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Chirality

• Objects that have non-superimposable mirror
  images are CHIRAL
• e.g., gloves, shoes, scissors
• Carbons are CHIRAL when there are 4 different
  atoms attached
• Molecules are CHIRAL if they have at least 1
  CHIRAL CARBON

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Fischer ProjectionsA Convenient Method For
Drawing Stereoisomers
Right-handed structure D-isomer
Left-handed structure L-isomer
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Amino Acids and Chirality
Glycine (Gly)
Alanine (Ala)
Valine (Val)
Leucine (Leu)
Methionine (Met)
Phenylalanine (Phe)
Tryptophan (Trp)
Isoleucine (Ile)
Proline (Pro)
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Tyrosine (Tyr)
Threonine (Thr)
Serine (Ser)
Glutamine (Gln)
Asparagine (Asn)
Cysteine (Cys)
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Aspartate (Aspartic acid) (Asp)
Glutamate (Glutamic acid) (Glu)
Lysine (Lys)
Histidine (His)
Arginine (Arg)
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Example
L-Dopa Anti-Parkinsons disease drug
D-Dopa Biologically inactive