Stereochemistry

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Stereochemistry

• Chemistry 223
• Fall 2008

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Isomers
Stereoisomers
Constitutional Isomers
Conformational Isomers
Configurational Isomers
Geometric Isomers
Optical Isomers
Enantiomers
Diastereomers
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Definitions

• Constitutional Isomers Compounds that have the
  same number of atoms but differ in the
  arrangement of atoms in the structure.
• Diethyl ether and Ethanol
• n-Butane and 2-methylpropane

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Definitions

• Stereoisomers Compounds with the same number of
  atoms and the same sequence of atoms, but which
  have a different arrangement of atoms in space.
• cis-But-2-ene and trans-But-2-ene
• gauche and anti conformations of butane
• 2 enantiomers of bromochloroiodomethane

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Definitions

• Conformational Isomers Compounds which differ by
  rotation around a carbon-carbon single bond.
• Conformational isomers for butane
• Chair, boat, half-chair conformations of
  cyclohexane

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Definitions

• Geometric Isomers Compounds with the same
  arrangement of atoms but which differ by rotation
  around a carbon-carbon double bond or a
  carbon-carbon bond in a cyclic hydrocarbon
• But-2-ene (cis and trans)
• 1,2-diethylcyclopropane (cis and trans)

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Definitions

• Optical Isomers Compounds which differ by the
  arrangement of atoms around a tetrahedral carbon
  or equivalent center.
• Enantiomers Non-superimposable mirror image
  isomers
• Diastereomers Non-superimposable, non mirror
  image isomers