The Inflection Point
- “Initial Tails” and “Final Heads”
- 3 Ways To Make OH A Better Leaving Group
- A Simple Formula For 7 Important Aldehyde/Ketone Reactions
- Acetoacetic
- Acids (Again!)
- Activating and Deactivating
- Actors In Every Acid Base Reaction
- Addition – Elimination
- Addition Pattern 1 – Carbocations
- Addition pattern 2 – 3 membered rings
- Addition Reactions
- Aldehydes And Ketones – Addition
- Alkene Pattern #3 – The “Concerted” Pathway
- Alkyl Rearrangements
- Alkynes – 3 Patterns
- Alkynes: Deprotonation and SN2
- Amines
- Aromaticity: Lone Pairs
- Avoid These Resonance Mistakes
- Best Way To Form Amines
- Bulky Bases
- Carbocation Stability
- Carbocation Stability Revisited
- Carboxylic Acids are Acids
- Chair Flips
- Cis and Trans
- Conformations
- Conjugate Addition
- Curved Arrow Refresher
- Curved Arrows
- Decarboxylation
- Determining Aromaticity
- Diels Alder Reaction – 1
- Dipoles: Polar vs. Covalent Bonding
- E2 Reactions
- Electronegativity Is Greed For Electrons
- Electrophilic Aromatic Substitution – Directing Groups
- Elimination Reactions
- Enantiocats and Diastereocats
- Enolates
- Epoxides – Basic and Acidic
- Evaluating Resonance Forms
- Figuring Out The Fischer
- Find That Which Is Hidden
- Formal Charge
- Frost Circles
- Gabriel Synthesis
- Grignards
- Hofmann Elimination
- How Acidity and Basicity Are Related
- How Are These Molecules Related?
- How Stereochemistry matters
- How To Stabilize Negative Charge
- How To Tell Enantiomers From Diastereomers
- Hybridization
- Hybridization Shortcut
- Hydroboration
- Imines and Enamines
- Importance of Stereochemistry
- Intermolecular Forces
- Intro to Resonance
- Ketones on Acid
- Kinetic Thermodynamic
- Making Alcohols Into Good Leaving Groups
- Markovnikov’s rule
- Mechanisms Like Chords
- Mish Mashamine
- More On The E2
- Newman Projections
- Nucleophiles & Electrophiles
- Nucleophilic Aromatic Substitution
- Nucleophilic Aromatic Substitution 2
- Order of Operations!
- Oxidation And Reduction
- Oxidative Cleavage
- Paped
- Pi Donation
- Pointers on Free Radical Reactions
- Protecting Groups
- Protecting Groups
- Proton Transfer
- Putting it together (1)
- Putting it together (2)
- Putting it together (3)
- Putting the Newman into ACTION
- Reaction Maps
- Rearrangements
- Recognizing Endo and Exo
- Redraw / Modify
- Robinson Annulation
- Robinson Annulation Mech
- Sigma and Pi Bonding
- SN1 vs SN2
- sn1/sn2 – Putting It Together
- sn1/sn2/e1/e2 – Exceptions
- sn1/sn2/e1/e2 – Nucleophile
- sn1/sn2/e1/e2 – Solvent
- sn1/sn2/e1/e2 – Substrate
- sn1/sn2/e1/e2 – Temperature
- Stereochemistry
- Strong Acid Strong Base
- Strong And Weak Oxidants
- Strong and Weak Reductants
- Stronger Donor Wins
- Substitution
- Sugars (2)
- Synthesis (1) – “What’s Different?”
- Synthesis (2) – What Reactions?
- Synthesis (3) – Figuring Out The Order
- Synthesis Part 1
- Synthesis Study Buddy
- Synthesis: Walkthrough of A Sample Problem
- Synthesis: Working Backwards
- t-butyl
- Tautomerism
- The 4 Actors In Every Acid-Base Reaction
- The Claisen Condensation
- The E1 Reaction
- The Inflection Point
- The Meso Trap
- The Michael Reaction
- The Nucleophile Adds Twice (to the ester)
- The One-Sentence Summary Of Chemistry
- The Second Most Important Carbonyl Mechanism
- The Single Swap Rule
- The SN1 Reaction
- The SN2 Reaction
- The Wittig Reaction
- Three Exam Tips
- Tips On Building Molecular Orbitals
- Top 10 Skills
- Try The Acid-Base Reaction First
- Two Key Reactions of Enolates
- What makes a good leaving group?
- What Makes A Good Nucleophile?
- What to expect in Org 2
- Work Backwards
- Zaitsev’s Rule
If you look at organic chemistry like a language course, the first five or six weeks focus on giving you the alphabet and learning how the words are formed. But now, things are going to start going fast, because we’re going to take all those “words” and start putting them together into meaningful sentences. In other words, “grammar”.
Up until now, organic chemistry has focused on structure. You’ve learned about bonding, isomers, conformations, and stereocenters. The only reactions you’ve done (besides some free radicals, possibly) have been acid-base reactions.
Just like only certain combinations of words “work” in English, only certain combinations of molecules, when combined together, will change their bonding. These events are called “reactions”, and there will be a few major patterns to learn.
That’s right: the focus of the next half of the course will be on reactions. And it will require a whole different mindset than the first half did. Things are going to move pretty fast.
- Every reaction you will learn involves a change in bonding. Because electrons are the currency of chemistry, and every reaction is a transaction of electrons between atoms, my best advice to you when you learn a new reaction is to first pay attention to one thing: what bonds are formed, and what bonds are broken.
- You will also notice that reactions change the charge on different atoms. So we’ll devote time to going over the factors that stabilize (and destabilize) charge on molecules, because this is going to be key for understanding why certain reactions happen and others don’t.
- Next, learn how to draw the curved arrows for each reaction, since this is the accounting system that will tell us what bonds are broken/formed and also how the charges change.
- Also, the stereochemistry of the molecule will often change during a reaction. This is probably the most testable facet of learning a new reaction. Like I said earlier, stereochemistry is probably the most important theme of Org 1.
- Finally, if learning it all forwards isn’t enough, inverting the questions – thinking backwards – is the last, important step towards mastering a reaction.
One of the reasons why students tend to fall behind in organic chemistry is that they aren’t prepared for this point in the course where things start to change. So go back and make sure you understand stereochemistry, conformations, acidity/basicity, dipoles, bonding, and how to interpret line diagrams, because these are all going to come into play over the rest of the course.
So what can you do to prepare? One word of advice: look for patterns. That’s what the focus of these posts will be on, from this point forward. There’s actually a small number of patterns to learn. We’ll go through them, don’t worry.
Tomorrow, we’ll go through one of the key reactions in organic chemistry: substitution.
Thanks for reading! James