(a)
Interpretation:Numbers of possible stereoisomeric products formed in the monobromination of racemic
Concept introduction:Halogenation products are governed by the achirality or already present stereocenter in the molecule.
If the halogenation occurs at the chiral center of the substrate it results in a racemic mixture. This is attributed to formation of achiral radical intermediate that can be attacked equally from the top face or bottom face. Thus two enantiomers R and S are formed in equal amount that makes the overall mixture optically inactive.
If the halogenation occurs at one of the two chiral centers of the substrate it results in change in absolute configuration at only one of the stereocenter and thus diastereoisomer result. These diastereomers are formed in unequal amounts.
(b)
Interpretation: Numbers of possible stereoisomeric products formed in the monobromination of racemic
Concept introduction:Halogenation products are governed by the achirality or already present stereocenter in the molecule.
If the halogenation occurs at the chiral center of the substrate it results in a racemic mixture. This is attributed to formation of achiral radical intermediate that can be attacked equally from the top face or bottom face. Thus two enantiomers R and S are formed in equal amount that makes the overall mixture optically inactive.
If the halogenation occurs at one of the two chiral centers of the substrate it results in change in absolute configuration at only one of the stereocenter and thus diastereoisomer result. These diastereomers are formed in unequal amounts.
(c)
Interpretation:Whether the various stereoisomeric products obtained from monobromination of racemic
Concept introduction:Halogenation products are governed by the achirality or already present stereocenter in the molecule.
If the halogenation occurs at the chiral center of the substrate it results in a racemic mixture. This is attributed to formation of achiral radical intermediate that can be attacked equally from the top face or bottom face. Thus two enantiomers R and S are formed in equal amount that makes the overall mixture optically inactive.
If the halogenation occurs at one of the two chiral centers of the substrate it results in change in absolute configuration at only one of the stereocenter and thus diastereoisomer result. These diastereomers are formed in unequal amounts.
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Organic Chemistry: Structure and Function
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- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning