Important Reduction Formulas for JEE and NEET

 Page 1


  
       
   
      
   
      
   
?  Points to remember in Reduction
(1) LiAlH
4
R?CHO
?? ?
 RCH
2
OH
?? ?
 
RCOOH
?? ?
R?CH
2
OH ?? ? 2R?CH
2
OH
  ?? ? RCH
2
OH + R?OH  ?? ? R?CH
2
NH
2
?? ? ?? ?
  ?? ? R?CH
2
OH R?CN ?? ?  R?CH
2
?NH
2
C = C / C?C ?? ?  No reaction
Exception :  Ph?CH=CH?COOH ?? ? Ph?CH
2
?CH
2
?CH
2
OH
(2) NaBH
4
, EtOH
Aldehyde ?? ? 1° Alcohol Ketone ?? ? 2 °Alcohol
Acid halide ?? ? 1° Alcohol
Page 2


  
       
   
      
   
      
   
?  Points to remember in Reduction
(1) LiAlH
4
R?CHO
?? ?
 RCH
2
OH
?? ?
 
RCOOH
?? ?
R?CH
2
OH ?? ? 2R?CH
2
OH
  ?? ? RCH
2
OH + R?OH  ?? ? R?CH
2
NH
2
?? ? ?? ?
  ?? ? R?CH
2
OH R?CN ?? ?  R?CH
2
?NH
2
C = C / C?C ?? ?  No reaction
Exception :  Ph?CH=CH?COOH ?? ? Ph?CH
2
?CH
2
?CH
2
OH
(2) NaBH
4
, EtOH
Aldehyde ?? ? 1° Alcohol Ketone ?? ? 2 °Alcohol
Acid halide ?? ? 1° Alcohol
  
(3) Na/EtOH (Bouvealt Blanc reduction)
Aldehyde ?? ? 1° Alcohol Ketone ?? ? 2º Alcohol
Acid halide ?? ? 1° Alcohol Ester ?? ?
 
Alcohol + Alcohol
RCN  ?? ?
 
RCH
2
NH
2
(4)  Na?Hg/HCl or
      Al[OCHMe
2
]
3
 
(MPV Reduction)
Aldehyde 
?? ?
 1° Alcohol Ketone
?? ?
2° Alcohol
(5) Rossenmund?s Reduction
  
? ? ? ? ? ? ? ?
4 2
BaSO / Pd / H
 R ? CH = O
(6) Birch reduction
      (Li/Na/K + Liquid NH
3
)
R?C?C?R ?? ?  (trans alkene)
     ?? ? 
Note : Terminal alkynes not reduced
(7) Stephen's Reduction
Note : DIBAL-H is also used for same conversion.
(8) Clemmensen Reduction
Page 3


  
       
   
      
   
      
   
?  Points to remember in Reduction
(1) LiAlH
4
R?CHO
?? ?
 RCH
2
OH
?? ?
 
RCOOH
?? ?
R?CH
2
OH ?? ? 2R?CH
2
OH
  ?? ? RCH
2
OH + R?OH  ?? ? R?CH
2
NH
2
?? ? ?? ?
  ?? ? R?CH
2
OH R?CN ?? ?  R?CH
2
?NH
2
C = C / C?C ?? ?  No reaction
Exception :  Ph?CH=CH?COOH ?? ? Ph?CH
2
?CH
2
?CH
2
OH
(2) NaBH
4
, EtOH
Aldehyde ?? ? 1° Alcohol Ketone ?? ? 2 °Alcohol
Acid halide ?? ? 1° Alcohol
  
(3) Na/EtOH (Bouvealt Blanc reduction)
Aldehyde ?? ? 1° Alcohol Ketone ?? ? 2º Alcohol
Acid halide ?? ? 1° Alcohol Ester ?? ?
 
Alcohol + Alcohol
RCN  ?? ?
 
RCH
2
NH
2
(4)  Na?Hg/HCl or
      Al[OCHMe
2
]
3
 
(MPV Reduction)
Aldehyde 
?? ?
 1° Alcohol Ketone
?? ?
2° Alcohol
(5) Rossenmund?s Reduction
  
? ? ? ? ? ? ? ?
4 2
BaSO / Pd / H
 R ? CH = O
(6) Birch reduction
      (Li/Na/K + Liquid NH
3
)
R?C?C?R ?? ?  (trans alkene)
     ?? ? 
Note : Terminal alkynes not reduced
(7) Stephen's Reduction
Note : DIBAL-H is also used for same conversion.
(8) Clemmensen Reduction
  
(9) Wolff-Kishner Reduction
 
R-X 
 
(10) Lindlar Catalyst
Note : H
2
, Pd, BaSO
4 
is also used for same conversion.
(11) Red Phosphorus and HI
Almost all functional groups contaning compounds converts into
corresponding alkane by red P + HI.
? R?CH
2
OH ?? R ? CH
3
? R?CHO ?? R ? CH
3
? R
2
CO ?? R
2
CH
2
 (Alkane)
(12) DIABAL-H reduction
  
Cold
H DIBAL
? ? ? ? ? ?
?
 RCH=O + R?OH
R?C?N 
? ? ? ? ? ?
?H DIBAL
  R?CH=O
At ordinary temperature esters reduced to alcohols but at low temperature esters
reduced to aldehyde.