JEE Organic Chemistry Quick Reference and Formula Sheet

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Basic Concepts

Named Reactions

Mechanism Summary

Important Formulas

Distinguishing Tests

Reagent Chart

Last Minute Tips

📚 Basic Concepts

IUPAC Nomenclature Rules

Priority Order of Functional Groups

1. Carboxylic acid (-COOH)
2. Anhydride (-CO-O-CO-)
3. Ester (-COOR)
4. Acid halide (-COX)
5. Amide (-CONH2)
6. Nitrile (-CN)
7. Aldehyde (-CHO)
8. Ketone (>C=O)
9. Alcohol (-OH)
10. Amine (-NH2)
11. Alkene (-C=C-)
12. Alkyne (-C≡C-)
13. Halide (-X)
14. Nitro (-NO2)

Numbering Rules

1. Longest chain containing principal functional group
2. Lowest locants to principal functional group
3. Multiple bonds get lowest numbers after functional group
4. Substituents get lowest possible numbers

Hybridization and Geometry

Electronic Effects

Inductive Effect (-I, +I)

• -I groups: -NO₂, -CN, -COOH, -F, -Cl, -Br, -I
• +I groups: -CH₃, -C₂H₅, -CH(CH₃)₂, -C(CH₃)₃

Resonance Effect

• +R groups: -OH, -OR, -NH₂, -NHR, -NR₂
• -R groups: -NO₂, -CN, -CO, -SO₃H

Hyperconjugation

• Stability order: (CH₃)₃C⁺ > (CH₃)₂CH⁺ > CH₃CH₂⁺ > CH₃⁺
• More alkyl groups = More hyperconjugation = More stability

⚗️ Named Reactions

Substitution Reactions

1. SN1 Reactions

• Mechanism: Two-step, carbocation intermediate
• Rate: Rate = k[substrate]
• Favors: Tertiary > Secondary > Primary
• Solvent: Polar protic
• Stereochemistry: Racemic mixture

2. SN2 Reactions

• Mechanism: One-step, backside attack
• Rate: Rate = k[substrate][nucleophile]
• Favors: Primary > Secondary > Tertiary
• Solvent: Polar aprotic
• Stereochemistry: Inversion of configuration

Elimination Reactions

3. E1 Reactions

• Mechanism: Two-step, carbocation intermediate
• Favors: Tertiary > Secondary > Primary
• Base: Weak base, polar protic solvent
• Product: More substituted alkene (Saytzeff)

4. E2 Reactions

• Mechanism: One-step, concert
• Favors: Primary > Secondary > Tertiary
• Base: Strong base, polar aprotic solvent
• Product: Less hindered alkene (Hoffman)

Important Named Reactions

5. Aldol Condensation

2CH₃CHO + NaOH → CH₃CH(OH)CH₂CHO → CH₃CH=CHCHO + H₂O

• Conditions: Dilute NaOH, 0-25°C
• Products: β-hydroxyaldehyde → α,β-unsaturated aldehyde

6. Cannizzaro Reaction

2HCHO + NaOH → CH₃OH + HCOONa

• Conditions: Concentrated NaOH, non-enolizable aldehydes
• Products: Alcohol + Carboxylate salt

7. Sandmeyer Reaction

C₆H₅N₂⁺Cl⁻ + CuX → C₆H₅X + N₂ + CuCl

• X = Cl, Br, CN: Halogenation, cyanation
• Cu/HCl: Hydrogenation

8. Friedel-Crafts Alkylation

C₆H₆ + RCl + AlCl₃ → C₆H₅R + HCl

• Catalyst: AlCl₃, FeCl₃
• Limitation: No rearrangement, polyalkylation

9. Friedel-Crafts Acylation

C₆H₆ + RCOCl + AlCl₃ → C₆H₅COR + HCl

• Advantage: No rearrangement, no polyacylation

10. Grignard Reaction

R-MgX + R'CHO → R-CH(OH)-R'

• Formation: R-X + Mg (dry ether) → R-MgX
• Reaction: With carbonyl compounds
• Workup: H₃O⁺

11. Williamson Ether Synthesis

R-X + R'ONa → R-O-R' + NaX

• Best for: Primary alkyl halides
• Limitation: Tertiary halides give elimination

12. Kolbe Electrolysis

2RCOO⁻ → R-R + CO₂ + 2e⁻

• Products: Symmetrical alkanes
• Mechanism: Free radical

🔄 Mechanism Summary

Reaction Mechanism Patterns

1. Electrophilic Addition

CH₂=CH₂ + HBr → CH₃CH₂Br

• Step 1: π bond attacks electrophile
• Step 2: Nucleophile attacks carbocation
• Regioselectivity: Markovnikov rule

2. Nucleophilic Addition

CH₃CHO + HCN → CH₃CH(OH)CN

• Step 1: Nucleophile attacks carbonyl carbon
• Step 2: Protonation of alkoxide
• Product: Cyanohydrin

3. Electrophilic Aromatic Substitution

C₆H₆ + Br₂/FeBr₃ → C₆H₅Br + HBr

• Step 1: Formation of electrophile
• Step 2: Aromatic ring attacks electrophile
• Step 3: Deprotonation

Stereochemistry Rules

1. R/S Configuration

1. Assign priorities (1 highest, 4 lowest)
2. Orient lowest priority group away
3. Trace 1→2→3: Clockwise = R, Counterclockwise = S

2. E/Z Configuration

1. Assign priorities to each double bond substituent
2. Higher priority groups on same side = Z
3. Higher priority groups on opposite sides = E

📊 Important Formulas

Degree of Unsaturation (DoU)

DoU = C + 1 + N/2 - H/2 - X/2

Where:

• C = number of carbons
• N = number of nitrogens
• H = number of hydrogens
• X = number of halogens

Molecular Formula Calculations

From Empirical Formula

Molecular Formula = (Empirical Formula) × n
where n = Molecular Weight / Empirical Formula Weight

Combustion Analysis

For CxHy:
CO₂ produced × (12/44) = Carbon in sample
H₂O produced × (2/18) = Hydrogen in sample

Acid-Base Calculations

pKa and pH

pH = pKa + log([A⁻]/[HA])

Buffer Capacity

Buffer capacity = moles of acid or base added per liter
to change pH by 1 unit

🧪 Distinguishing Tests

Aldehyde vs Ketone Tests

Alcohol Classification Tests

Phenol vs Alcohol Tests

🧫 Reagent Chart

Oxidizing Agents

Reducing Agents

Bases

🎯 Last Minute Tips

Exam Strategy

1. Question Approach

1. Read carefully - Identify what’s being asked
2. Identify the concept - Recognize the reaction type
3. Recall the mechanism - Step-by-step thinking
4. Apply the rules - Use systematic approach
5. Verify the answer - Check for common mistakes

2. Time Management

• Easy questions: 2-3 minutes
• Medium questions: 5-7 minutes
• Hard questions: 8-10 minutes
• Leave time: 15 minutes for review

3. Common Mistakes to Avoid

1. Wrong numbering in nomenclature
2. Missing stereochemistry in products
3. Incorrect mechanism application
4. Wrong reagent selection
5. Calculation errors in formulas

Memory Aids

Mnemonics for Functional Group Priority

"Can An Eagle Add More Nuts To His Cage"
Carboxylic > Anhydride > Ester > Acid halide > Amide > Nitrile >
Aldehyde > Ketone > Alcohol > Amine > Alkene > Alkyne > Halide > Nitro

Substituent Effects

"EDG = Electron Donating Groups = More Reactive"
"EWG = Electron Withdrawing Groups = Less Reactive"

Aromatic Substitution

"OOPS = Ortho, Para, Strongly activating"
"OPS = Ortho, Para, Strongly deactivating"

Quick Calculations

Molecular Weight Estimation

• C: 12, H: 1, O: 16, N: 14, Cl: 35.5, Br: 80
• Round to nearest integer for quick estimates

Degree of Unsaturation

• Each ring = 1 DoU
• Each double bond = 1 DoU
• Each triple bond = 2 DoU
• Each benzene ring = 4 DoU

📱 Emergency Reference

Must-Know Reactions (Top 10)

1. SN1/SN2 - Substitution mechanisms
2. E1/E2 - Elimination mechanisms
3. Aldol Condensation - Carbon-carbon bond formation
4. Cannizzaro Reaction - Disproportionation
5. Grignard Reaction - Carbon-carbon bond formation
6. Friedel-Crafts - Aromatic substitution
7. Ozonolysis - Alkene cleavage
8. Diels-Alder - Cycloaddition
9. Hoffmann Elimination - Quaternary ammonium
10. Beckmann Rearrangement - Oxime to amide

Critical Concepts

1. Resonance stabilization
2. Inductive effects
3. Hyperconjugation
4. Stereochemistry rules
5. Acidity/basicity trends
6. Solvent effects
7. Temperature effects
8. Catalyst functions

Exam Day Checklist

• ID card and stationery
• Watch for time management
• Water and light snack
• Good night’s sleep
• Reach center early
• Stay calm and focused

Remember: Organic Chemistry is about understanding patterns and mechanisms, not memorization. Stay calm, think systematically, and trust your preparation!

Best of luck for your JEE examination!

Last Updated: October 2024