This document discusses various organic chemistry reaction mechanisms. It summarizes 7 reaction mechanisms - Arndt-Eistert reaction, Baeyer-Villiger oxidation, Grignard's reaction, Diels Alder reaction, Friedel Crafts reaction, Canizaros reaction, and Wolf-Kishner reduction. It also discusses metal hydride reductions using reagents like sodium borohydride, lithium aluminium hydride, and their reaction steps and uses in reducing carbonyl, carboxylic acid, and ester groups.

1. ORGANIC CHEMISTRY
Reaction Mechanisms.
Group Members:-
Tayyab Ayub
Ahmed Nawaz
Amjad Rasheed
Ahtasham Tufail Bajwa
Muhammad Huzaifa

2. Reaction Mechanisms
1-Arndt-Eistert reaction
The Arndt-Eistert Synthesis allows the formation of homologated carboxylic
acids or their derivatives by reaction of the activated carboxylic acids with
diazomethane and subsequent Wolff-Rearrangement of the intermediate
diazo ketones in the presence of nucleophiles such as water, alcohols, or
amines.
 General Reaction
 Reaction Mechanism
Step 1(Re-arrangement)
Step 2(Nucleophillic Attack)

3. Step 3(Removal of Leavng Group)
Step 4(Deprotonation)
Step 5(Rearrangement)
Step 6(Removal of N2)

4. Step 7(Formation of Ketene)
Step 8(Hydration)
Step 9(Resonance)
Step 10(Tautomerism)

5. 2-Baeyer-Villiger oxidation
The Baeyer–Villiger oxidation is an organic reaction that forms
an ester from a ketone or a lactone from a cyclic ketone
using peroxyacids or peroxides as the oxidant.
 General Reaction
 Mechanism
Step 1(protontion)
Step 2(Nucleophillic Attack)

6. Step 3(Deprotonation)
Step 4(Spilitting)
Step 5(Redox Reaction)

7. 3-Grignard’s Reaction
The Grignard Reaction is the addition of an organometallc halide (Grignard
reagent) to a ketone or aldehyde, to form a tertiary or secondary alcohol,
respectively. The reaction with formaldehyde leads to a primary alcohol.
 Reaction with Aldehyde
 Mechanism
Step 1(Nucleophillic Attack)
Step 2(Hydrolysis)

8. Reaction with Ketone
 Mechanism
Step 1(Nucleophillic Attack)
Step 2(Hydrolysis)
4-Diels Alder Reaction

9. Diels–Alder reaction is a chemical reaction between a conjugated diene and
an alkene or alkyne, commonly termed the dienophile, to form a substituted
cyclohexene derivative. It is the prototypical example of a pericyclic
reaction .
 Reaction
 MECHANSISM
Step 1(Rearrangement)
Step 2(Nucleophillic Attack)

10. 5-Friedel Craft’s reaction
This electrophilic aromatic substitution allows the synthesis of
monoacylated products from the reaction between arenes and acyl
chlorides or anhydrides and HX is removed.
 Reaction
 Mechanism

11. Step 1(Generation of Electrophile)
Step 2(Electrophillic Attack)
Step 3(Dehydrogenation)
6-Canizaros Reaction
The reduction of aldehydes and ketones to alkanes. Condensation of the carbonyl compound with
hydrazine forms the hydrazone, and treatment with base induces the reduction of the carbon coupled with
oxidation of the hydrazine to gaseous nitrogen, to yield the corresponding alkane.
Those compounds (Aldehyde) which have no alpha-hydrogen undergoes canizaro’s reaction.
it is disproportional (Oxidation-Reduction) Reaction.
In which 2 molecules of aldehyde are involved , one molecule is reduced to alcohol while other is oxidized
to acid (Sodium salt of Carboxylic Acid)
This Reaction is Carried at 50% Aqueous NaOH
Formaldehyde and Benzalaldehyde also give Canizoros reaction
 General Reaction

12.  Mechanism
Step 1(Ionization)
Step 2(Nucleophillic Attack)
Step 3(Removal of Hydride)

13. Step 4(Hydride Attack)
Step 5(Redox Reaction)
Step 6(Reaction with Base)

14. 7-Wolf-Kishner’s Reduction
The Wolff–Kishner reduction is a reaction used in organic chemistry to
convert carbonyl functionalities into methylene groups.
 General Reaction
 Mechanism
Step 1(Nucleophillic Attack)

15. Step 2(Deprotonation)
Step 3(Hydrolysis)
Step 4(Dehydration)
Step 5(Dehydration)

16. Step 6(Protonation)
Step 7(Attack of Base)
Step 8(Hydrolysis)

17. 8-Perkin reaction
It is an organic reaction used to make cinnamic acid. It gives an α,β-
unsaturated aromatic acid by the aldol condensation of
an aromatic aldehyde and an acid anhydride, in the presence of an alkali salt
of acid.
 General Reaction
 Mechanism
Step 1(Ionization)

18. Step 2(attack of Base)
Step 3(Nucleophillic Attack)
Step 4(Protonation)
Step 5(Dehydration)

19. 9-Metal Hydride Reduction
Metal Hydride Reduction are probably most widely used, followed by
Catalytic Hydrogenation.
 Boron reagent
Boron based reagents are
 Sodium Borohydride - 𝑁𝑎𝐵𝐻4
 Sodium Cynoborohydride 𝑁𝑎𝐶𝑁𝐵𝐻3
 Sodium Tricetobrohydride 𝑁𝑎(𝑂𝐴𝑐)3𝐵𝐻
 Lithium Borohydride 𝐿𝑖𝐵𝐻4
 Potassium Borohydride 𝐾𝐵𝐻4
 Tetramethylammonium BoroHydride
LiAlH4 is stronger reducing agent then NaBH4 due to weaker Al-H bond, and
isused to reduce compound that are non reactive to NaBH4
 Sodium Borohydride
Sodium Borohydride was first Prepared by reaction of Sodium Hydride with
tetra Methylborate
𝐿𝑖𝐴𝑙𝐻4 is less reactive than 𝑁𝑎𝐵𝐻4
It is only powerful to reduce aldehyde, ketone and Acid Cholorides to
Alcohols

20. Ester , Amide and Nitriles are Largely Unaffected
Aldehyde is reduced to Primary Alcohol while Ketone is reduced to Secondry
Alcohol
Chemoselectivly Reagent
 Lithium Aluminium Hydride
Very powerful redusing agent ,Avilibele as powder and Pallet
Used as suspension in Ether or THF
Reacts Voilently with water, Alcohol
Reduces Carbonyl, Carvoxylic Acid & Ester
Reduces Nitrile , Amide and Acyl Nitro groups to Amine
Reduces Acetylene to Olefins
Reduces C-X bond & opens Epoxide