Pharmaceutical Organic chemistry, Stereoselective and stereospecific reaction

1. STEREOSPECIFICITY
&
STEREOSELECTIVITY
STEREOSPECIFICITY
&
STEREOSELECTIVITY
Explanation by Dr. Atul R. Bendale
Definitio
n
Concep
t
Selectiv
e
specific
exampl
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follow

2. Definition
Concep
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Selectiv
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specific
exampl
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follow
STEREO SPECIFIC
In a stereospecific reaction, one stereoisomer of the reactant gives one
stereoisomer of the product, while a different stereoisomer of the
reactant gives a different stereoisomer of the product (like in SN2)
STEREO SELECTIVE
A stereoselective reaction is one in which a single reactant can
give two or more stereoisomeric products, and one or more of
these products is preferred over the others – even if the
preference is very small (minor product).

3. Definitio
Concep
t
Selectiv
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specific
exampl
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follow
Stereoselecti
ve
2
Stereospecifi
c
1
Stereoselecti
ve
2
Two
productsOne is major,
other is minor
One product
Depend upon
stereochemistry
of reactant
has 2 sub
classes1.
entaioselective
2.
distereoselecive

4. Definitio
Concep
t
Selectiv
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specific
exampl
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In this reaction we get multiple products (major and minor) from one
reactant by applying specific condition.
By apply different condition on same reactant we got different major
and minor products.
So in this reaction we have option to choose products (major and
minor).

5. Definitio
Concep
t
Selectiv
e
specific
exampl
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follow

6. Definitio
Concep
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Selectiv
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exampl
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01
02
01
So Bromine
Is added
From LEFT hand side
So
bromine
Is added from
RIGHT hand side
02
In above
structureChlorine is
At LEFT hand side
In above
structure
Chlorine is
Present at RIGHT hand
side
The point of attachment of bromine is depend upon
Position of chlorine group
Therefore it is streospecific reaction

7. Definitio
Concep
t
Selectiv
e
specific
exampl
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follow STEREO SELECTIVE
Following 4 examples shows
stereo selectivity
STEREO SPECIFIC
Following 3 examples shows
stereo specificity

8. Definitio
Concep
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Selectiv
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specific
exampl
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