As seen on

Organic Chemistry Is Awesome
Over 300+ blog posts to guide you through introductory Organic Chemistry, organized by subject.
00 General Chemistry Review
- Gen Chem and Organic Chem: How are they different?
- How Gen Chem Relates to Organic Chem, Pt. 1 - The Atom
- From Gen Chem to Organic Chem, Pt. 2 - Electrons and Orbitals
- From Gen Chem to Organic Chem, Pt. 3 - Effective Nuclear Charge
- From Gen Chem to Organic Chem, Pt. 4 - Chemical Bonding
- From Gen Chem to Organic Chem, Pt. 5 - Understanding Periodic Trends
- From Gen Chem to Org Chem, Pt. 6 - Lewis Structures, A Parable
- From Gen Chem to Org Chem, Pt. 7 - Lewis Structures
- From Gen Chem to Org Chem, Pt. 8 - Ionic and Covalent Bonding
- From Gen Chem to Org Chem, Pt. 9 - Acids and Bases
- From Gen Chem to Organic Chem, Pt. 10 - Hess' Law
- From Gen Chem to Organic Chem, Pt. 11 - The Second Law
- From Gen Chem to Org Chem Pt. 12 - Kinetics
- From Gen Chem to Organic Chem, Pt. 13 - Equilibria
- From Gen Chem to Organic Chem, Part 14: Wrapup
01 Bonding, Structure, and Resonance
- How Concepts Build Up In Org 1 ("The Pyramid")
- Review of Atomic Orbitals for Organic Chemistry
- How Do We Know Methane Is Tetrahedral?
- Hybrid Orbitals
- A Hybridization Shortcut
- Hybridization And Bond Strengths
- Sigma bonds come in six varieties: Pi bonds come in one
- A Key Skill: How to Calculate Formal Charge
- Partial Charges Give Clues About Electron Flow
- The Four Intermolecular Forces and How They Affect Boiling Points
- 3 Trends That Affect Boiling Points
- How To Use Electronegativity To Determine Electron Density (and why NOT to trust formal charge)
- Introduction to Resonance
- How To Use Curved Arrows To Interchange Resonance Forms
- Evaluating Resonance Forms (1) - The Rule of Least Charges
- Evaluating Resonance Forms (2): Applying Electronegativity
- Evaluating Resonance Forms: Factors That Stabilize Negative Charges
- Evaluating Resonance Forms (4): Positive Charges
- Exploring Resonance: Pi-Donation
- Exploring Resonance: Pi-acceptors
- In Summary: Resonance
- Drawing Resonance Structures: 3 Common Mistakes To Avoid
- How to apply electronegativity and resonance to understand reactivity
02 Acid Base Reactions
- Introduction to Acid-Base Reactions
- Walkthrough of Acid Base Reactions (1)
- Walkthrough of Acid Base Reactions (2): Basicity
- Walkthrough of Acid-Base Reactions (3) - Acidity Trends
- Five Key Factors That Influence Acidity
- Walkthrough of Acid-Base reactions (4) - pKa
- How to Use a pKa Table
- The pKa Table Is Your Friend
- A Handy Rule of Thumb for Acid-Base Reactions
- Acid Base Reactions Are Fast
- Putting Acidity In Perspective
- Acid Base Reactions: What's the Point?
03 Alkanes and Nomenclature
- Summary Sheet - Alkane Nomenclature
- Meet the (Most Important) Functional Groups
- Condensed Formulas: Deciphering What the Brackets Mean
- Hidden Hydrogens, Hidden Lone Pairs, Hidden Counterions
- Don't Be Futyl, Learn The Butyls
- Primary, Secondary, Tertiary, Quaternary In Organic Chemistry
- Branching, and Its Affect On Melting and Boiling Points
- The Many, Many Ways of Drawing Butane
- Common Mistakes: Drawing Tetrahedral Carbons
- Common Mistakes in Organic Chemistry: Pentavalent Carbon
- Table of Functional Group Priorities for Nomenclature
- Organic Chemistry IUPAC Nomenclature Demystified With A Simple Puzzle Piece Approach
04 Conformations and Cycloalkanes
- Conformations
- Newman Projections
- Putting the Newman into ACTION
- Introduction to Cycloalkanes (1)
- Cis And Trans Cycloalkanes
- Cycloalkanes - How To Calculate Ring Strain
- Cycloalkanes - Ring Strain In Cyclopropane And Cyclobutane
- Ring Strain in Cyclopentane and Cyclohexane
- An Aerial Tour Of The Cyclohexane Chair
- How To Draw A Cyclohexane Chair
- The Cyclohexane Chair Flip
- The Cyclohexane Chair Flip - Energy Diagram
- Substituted Cyclohexanes - Equatorial vs Axial
- Substituted Cyclohexanes: "A Values"
- The Ups and Downs of Cyclohexanes
- Which Cyclohexane Chair Is Of Lower Energy?
- Fused Rings
- Bridged Bicyclic Rings (And How To Name Them)
- Bredt's Rule (And Summary of Cycloalkanes)
05 A Primer On Organic Reactions
- The Most Important Question To Ask When Learning a New Reaction
- The 4 Major Classes of Reactions in Org 1
- Learning New Reactions: How Do The Electrons Move?
- How (and why) electrons flow
- The Third Most Important Question to Ask When Learning A New Reaction
- 7 Factors that stabilize negative charge in organic chemistry
- 7 Factors That Stabilize Positive Charge in Organic Chemistry
- Common Mistakes: Formal Charges Can Mislead
- Nucleophiles and Electrophiles
- Curved Arrows (for reactions)
- Curved Arrows (2): Initial Tails and Final Heads
- Nucleophilicity vs. Basicity
- The Three Classes of Nucleophiles
- What Makes A Good Nucleophile?
- Leaving Groups Are Nucleophiles Acting In Reverse
- What makes a good leaving group?
- 3 Factors That Stabilize Carbocations
- Three Factors that Destabilize Carbocations
- What's a Transition State?
- Hammond's Postulate
- Grossman's Rule
- Draw The Ugly Version First
- Learning Reactions: A Checklist (PDF)
- Introduction to Addition Reactions
- Introduction to Elimination Reactions
- Introduction to Free Radical Substitution Reactions
- Introduction to Oxidative Cleavage Reactions
06 Free Radical Reactions
- Bond Dissociation Energies = Homolytic Cleavage
- Free Radical Reactions
- 3 Factors That Stabilize Free Radicals
- What Factors Destabilize Free Radicals?
- Bond Strengths And Radical Stability
- Free Radical Initiation: Why Is "Light" Or "Heat" Required?
- Initiation, Propagation, Termination
- Isomers From Free Radical Reactions
- Selectivity In Free Radical Reactions
- Selectivity in Free Radical Reactions: Bromine vs. Chlorine
- Halogenation At Tiffany's
- Allylic Bromination
- Bonus Topic: Allylic Rearrangements
- In Summary: Free Radicals
- Synthesis (2) - Reactions of Alkanes
07 Stereochemistry and Chirality
- On Cats, Part 4: Enantiocats
- On Cats, Part 6: Stereocenters
- The Single Swap Rule
- Introduction to Assigning (R) and (S): The Cahn-Ingold-Prelog Rules
- Determining R/S (2) - The Method of Dots
- Types of Isomers: Constitutional Isomers, Stereoisomers, Enantiomers, and Diastereomers
- Enantiomers vs Diastereomers vs The Same? Two Methods For Solving Problems
- Assigning R/S To Newman Projections (And Converting Newman To Line Diagrams)
- The Meso Trap
- Optical Rotation, Optical Activity, and Specific Rotation
- Optical Purity and Enantiomeric Excess
- What's a Racemic Mixture?
- Chiral Allenes And Chiral Axes
08 Substitution Reactions
- Introduction to Nucleophilic Substitution Reactions
- Walkthrough of Substitution Reactions (1) - Introduction
- Two Types of Substitution Reactions
- The SN2 Mechanism
- Why the SN2 Reaction Is Powerful
- The SN1 Mechanism
- The Conjugate Acid Is A Better Leaving Group
- Comparing the SN1 and SN2 Reactions
- Polar Protic? Polar Aprotic? Nonpolar? All About Solvents
- Steric Hindrance is Like a Fat Goalie
- Common Blind Spot: Intramolecular Reactions
- The Conjugate Base is Always a Stronger Nucleophile
09 Elimination Reactions
- Walkthrough of Elimination Reactions (1)
- Elimination Reactions (2): Zaitsev's Rule
- Elimination Reactions Are Favored By Heat
- Two Types of Elimination Reactions
- The E1 Reaction
- The E2 Mechanism
- Comparing the E1 and E2 Reactions
- The E2 Reaction and Cyclohexane Rings
- Bulky Bases in Elimination Reactions
- Comparing the E1 and SN1 Reactions
- Elimination (E1) Reactions With Rearrangements
10 Rearrangements
11 SN1/SN2/E1/E2 Decision
12 Alkene Reactions
- Alkene Nomenclature: Cis and Trans and E and Z
- Addition Reactions: Elimination's Opposite
- Selective vs. Specific
- Addition Reactions: Regioselectivity
- Addition Reactions: Stereochemistry
- Markovnikov's Rule (1)
- Markovnikov's Rule (2) - Why It Works
- Curved Arrows and Addition Reactions
- Addition Pattern #1: The "Carbocation Pathway"
- Rearrangements in Alkene Addition Reactions
- Bromination of Alkenes - How Does It Work?
- Bromination of Alkenes: The Mechanism
- Alkene Addition Pattern #2: The "Three-Membered Ring" Pathway
- Hydroboration of Alkenes
- Hydroboration of Alkenes: The Mechanism
- Alkene Addition Pattern #3: The "Concerted" Pathway
- An Arrow-Pushing Dilemma In Concerted Reactions
- A Fourth Alkene Addition Pattern - Free Radical Addition
- Alkene Reactions: Ozonolysis
- Summary: Alkene Reaction Pathways
- Synthesis (4) - Reactions of Alkenes
13 Alkyne Reactions
- The 2 Most Important Reactions of Alkynes
- Partial Reduction of Alkynes To Obtain Cis or Trans Alkenes
- Hydroboration and Oxymercuration of Alkynes
- Alkyne Reaction Patterns - The Carbocation Pathway
- Alkyne Addition Reactions: The 3-Membered Ring Pathway
- Alkyne Addition Reactions - The "Concerted" Pathway
- Alkynes Via Elimination Reactions
- Alkynes Are A Blank Canvas
- Synthesis (5) - Reactions of Alkynes
14 Alcohols, Epoxides and Ethers
- Alcohols (1) - Nomenclature and Properties
- How To Make Alcohols More Reactive
- Alcohols (3) - Acidity and Basicity
- The Williamson Ether Synthesis
- Williamson Ether Synthesis: Planning
- Synthesis of Ethers (2) - Back To The Future
- Ether Synthesis Via Alcohols And Acid
- Cleavage Of Ethers With Acid
- Epoxides - The Outlier Of The Ether Family
- Opening Of Epoxide With Base
- Opening of Epoxides With Acid
- Making Alkyl Halides From Alcohols
- Tosylates And Mesylates
- PBr3 and SOCl2
- Elimination Reactions of Alcohols
- Elimination of Alcohols To Alkenes With POCl3
- Alcohol Oxidation: "Strong" and "Weak" Oxidants
- Demystifying Alcohol Oxidations
- Intramolecular Reactions of Alcohols and Ethers
- Protecting Groups For Alcohols
- Thiols And Thioethers
- Calculating the oxidation state of a carbon
- Oxidation and Reduction in Organic Chemistry
- Oxidation Ladders
- SOCl2 and the SNi Mechanism
- Synthesis (6) - Reactions of Alcohols
15 Organometallics
- What's An Organometallic?
- Synthesis of Grignard and Organolithium Reagents
- Organometallics Are Strong Bases
- Reactions of Grignard Reagents
- Protecting Groups In Grignard Reactions
- Synthesis Using Grignard Reagents (1)
- Grignard Reactions And Synthesis (2)
- Gilman Reagents (Organocuprates): How They're Made
- Gilman Reagents (Organocuprates): What They're Used For
- Common Mistakes with Carbonyls: Carboxylic Acids... Are Acids!
- The Heck, Suzuki, and Olefin Metathesis Reactions (And Why They Don't Belong In Most Introductory Organic Chemistry Courses)
- Reaction Map: Reactions of Organometallics
16 Spectroscopy
- Degrees of Unsaturation (Index of Hydrogen Deficiency)
- How Bleach Works: Understanding Colors From Nature
- Introduction To UV-Vis Spectroscopy
- UV-Vis Spectroscopy: Absorbance of Carbonyls
- UV-Vis Spectroscopy: Some Practice Questions
- Bond Vibrations, IR Spectroscopy, and the "Ball and Spring" Model
- Infrared Spectroscopy: A Quick Primer On Interpreting Spectra
- IR Spectroscopy: Some Simple Practice Problems
- Homotopic, Enantiotopic, Diastereotopic
- Liquid Gold: Pheromones In Doe Urine
- Natural Product Isolation (1) - Extraction
- Natural Product Isolation (2) - Purification of Crude Mixtures Overview
- Structure Determination Case Study: Deer Tarsal Gland Pheromone
17 Dienes and MO Theory
- What To Expect In Organic Chemistry 2
- How Concepts Build Up In Org 2
- Are these molecules conjugated?
- Conjugation and Resonance
- Molecular Orbital Diagram For A Simple Pi Bond - Bonding And Antibonding
- Molecular Orbitals of The Allyl Cation, Allyl Radical, and Allyl Anion
- Pi Molecular Orbitals of Butadiene
- Reactions of Dienes: 1,2 and 1,4 Addition
- Thermodynamic and Kinetic Control
- More On 1,2 and 1,4 Additions To Dienes
- s-cis and s-trans
- The Diels-Alder Reaction
- Cyclic Dienes and Dienophiles in the Diels-Alder Reaction
- Stereochemistry of the Diels-Alder Reaction
- Exo vs Endo Products In The Diels Alder: How To Tell Them Apart
- Molecular Orbitals in the Diels Alder Reaction
- Why Are Endo vs Exo Products Favored in the Diels-Alder Reaction?
- Diels-Alder Reaction: Kinetic and Thermodynamic Control
- The Retro Diels-Alder Reaction
- Regiochemistry In The Diels-Alder Reaction
18 Aromaticity
19 Reactions of Aromatic Molecules
- Electrophilic Aromatic Substitution: Introduction
- Activating and Deactivating Groups In Electrophilic Aromatic Substitution
- Electrophilic Aromatic Substitution - The Mechanism
- Ortho-, Para- and Meta- Directors in Electrophilic Aromatic Substitution
- Understanding Ortho, Para, and Meta Directors
- Why are halogens ortho- para- directors?
- Disubstituted Benzenes: The Strongest Electron-Donor "Wins"
- Electrophilic Aromatic Substitutions (1) - Halogenation
- Electrophilic Aromatic Substitutions (2) - Nitration and Sulfonation
- EAS Reactions (3) - Friedel-Crafts Acylation and Friedel-Crafts Alkylation
- Intramolecular Friedel-Crafts Reactions
- Nucleophilic Aromatic Substitution (NAS)
- Nucleophilic Aromatic Substitution (2) - The Benzyne Mechanism
- Reactions of Diazonium Salts: Sandmeyer and Related Reactions
- Reactions on the "Benzylic" Carbon: Bromination And Oxidation
- The Wolff-Kishner, Clemmensen, And Other Carbonyl Reductions
- More Reactions on the Aromatic Sidechain: Reduction of Nitro Groups and the Baeyer Villiger
- Aromatic Synthesis (1) - "Order Of Operations"
- Aromatic Synthesis (2) - Polarity Reversal
- Aromatic Synthesis (3) - Sulfonyl Blocking Groups
- Synthesis (7): Reaction Map of Benzene and Related Aromatic Compounds
20 Aldehydes and Ketones
- Weird Nomenclature In Carbonyl Chemistry
- The Simple Two-Step Pattern For Seven Key Reactions of Aldehydes and Ketones
- Wittig Reaction
- Imines and Enamines
- Acid Catalysis Of Carbonyl Addition Reactions: Too Much Of A Good Thing?
- On Acetals and Hemiacetals
- Carbonyl Chemistry: 10 Key Concepts (Part 1)
- Carbonyls: 10 key concepts (Part 2)
- Breaking Down Carbonyl Reaction Mechanisms: Anionic Nucleophiles (Part 1)
- Breaking Down Carbonyl Reaction Mechanisms: Reactions of Anionic Nucleophiles (Part 2)
21 Carboxylic Acid Derivatives
- Simplifying the reactions of carboxylic acid derivatives (part 1)
- Carbonyl Mechanisms: Neutral Nucleophiles, Part 1
- Carbonyl chemistry: Anionic versus Neutral Nucleophiles
- Proton Transfers Can Be Tricky
- Let's Talk About the [1,2] Elimination
- Carbonyl Chemistry: Learn Six Mechanisms For the Price Of One
- Summary Sheet #5 - 9 Key Mechanisms in Carbonyl Chemistry
- Summary Sheet #7 - 21 Carbonyl Mechanisms on 1 page
- How Reactions Are Like Music
- Making Music With Mechanisms
- The Magic Wand of Proton Transfer
- The Power of Acid Catalysis
22 Enols and Enolates
23 Amines
- Amides: Properties, Synthesis, and Nomenclature
- Basicity of Amines And pKaH
- 5 Factors That Affect Basicity of Amines
- The Mesomeric Effect And Aromatic Amines
- Nucleophilicity of Amines
- Alkylation of Amines (Sucks)
- Reductive Amination
- The Gabriel Synthesis
- Some Reactions of Azides
- The Hofmann Elimination
- The Hofmann and Curtius Rearrangements
- The Cope Elimination
- Protecting Groups for Amines - Carbamates
- Introduction to Peptide Synthesis
- The Strecker Synthesis of Amino Acids
24 Carbohydrates
- D and L Sugars
- What is Mutarotation?
- Reducing Sugars
- Pyranoses and Furanoses: Ring-Chain Tautomerism In Sugars
- The Big Damn Post Of Sugar Nomenclature
- The Haworth Projection
- Converting a Fischer Projection To A Haworth (And Vice Versa)
- Reactions of Sugars: Glycosylation and Protection
- The Ruff Degradation and Kiliani-Fischer Synthesis
25 Fun and Miscellaneous
- Organic Chemistry and the New MCAT
- A Gallery of Some Interesting Molecules From Nature
- The Organic Chemistry Behind "The Pill"
- Maybe they should call them, "Formal Wins" ?
- Introduction To Synthesis
- Organic Chemistry Is Shit
- The 8 Types of Arrows In Organic Chemistry, Explained
- The Most Annoying Exceptions in Org 1 (Part 1)
- The Most Annoying Exceptions in Org 1 (Part 2)
- Org 1 Review Quizzes
- Screw Organic Chemistry, I'm Just Going To Write About Cats
- On Cats, Part 1: Conformations and Configurations
- On Cats, Part 2: Cat Line Diagrams
- The Marriage May Be Bad, But the Divorce Still Costs Money
- Why Do Organic Chemists Use Kilocalories?
- What Holds The Nucleus Together?
- 9 Nomenclature Conventions To Know
See what’s inside
Case Studies Of Successful Students
From The Blog
James Ashenhurst
Founder, Master Organic Chemistry
After doing a Ph. D. in organic synthesis at McGill and a postdoc at MIT, I applied for faculty positions at universities. It didn’t work out. But having seen first-hand how many people struggled with the subject (including myself when I took it as an undergraduate) I thought there was a need for an online organic chemistry resource that had all the rigor of a traditional textbook, but was more approachable and accessible.
Drawing on the experience of thousands of hours spent tutoring students 1-on-1, as well as dozens of case studies, Master Organic Chemistry aims to fill in some of the conceptual gaps that aren’t traditionally covered by textbooks, and provide a friendly, logical and thorough pathway for learning introductory organic chemistry.
