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method of prepration of aldehyde and ketone combine (एल्डिहाइड और कीटोन बनाने की विधियां कंबाइन)

1.) Oxidation of alcohols (एल्कोहल के ऑक्सीकरण से):

1° alcohols -----[o]-----> aldehyde -----[o]-----> carboxylic acid

2° alcohols -----[o]-----> ketones

3° alcohols -----[o]-----> no oxidation❌

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Case 1 : oxidation by mild(weak) oxidising agents

1° alcohols -----[o](mild o. a.)-----> aldehyde

2° alcohols -----[o](mild o. a.)-----> ketones

mild oxidising agents
1. pcc (pyridinium chloro chromate)
2. pdc (pyridinium dichtomate )
3. Cro₃ + accetone


4. Cro₃ + ( collin's reagent)
5. Cu or Ag at 300°c

   1° alcohols + (Cu at 300°c)-----> aldehyde

   2° alcohols + ( Ag at 300°c)-----> ketones

   3° alcohols + [Ag or Cu at 300°c]----> alkene by E² mach.

   


6. MnO₂ (used only for allylic & Benzylic alcohols only)

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Case 2 : oxidation by strong oxidising agents(SOA) :

1° alcohols -----[o]-----> carboxylic acid

2° alcohols -----[o]-----> ketones

3° alcohols -----[o]-----> no oxidation❌

strong oxidising agents

1. KMnO₄/H⁺, Hot KMnO₄
2. K₂Cr₂O₇/H⁺, Hot K₂Cr₂O₇
3. CrO₃ + H₂SO₄(Jon's reagents)
4. CrO₃(aq.) + H₂CrO₄
5. conc. HNO₃

Method of preprⁿ of Aldehyde

1.)रोज़नमुड reduction

Reagent: H₂+ Pd/BaSO₄(Lindlar's catalyst)

R-CO-Cl ------Reagent---------->R-CHO +HCl

2.)Stephen's Reduction

Reagent:

• 1.)SnCl₂+ HCl,
• 2.)H₃O⁺

R-CN -----Reagent------->R-CHO

3.)Dibal-H (di-iso-butyl aluminium hydride)

Reagent:

1. Dibal-H
2. H₂

R-CO-OR' --Reagent-----> R-CH₂-OH + R'-OH

R-CN --Reagent-----> R-CHO

4.)Etard reaction

5.)side chain oxidation

Reagent:

1. Cl₂
2. aq. KOH or H₃O⁺

6.)गाटरमैन कोच Reaction