For orgo, what are the concepts that I should understand? To me, all of it seems

Lewis Structures

Acids/Bases


Electronegativity
Hydrogen Bonding
Resonance

The answer is almost always going to be resonance, enantiomers or a crazy branching stick drawing

jm192 said:

Lewis Structures

Acids/Bases


Electronegativity
Hydrogen Bonding
Resonance

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And electron pushing

I would specifically emphasize the concept of Lewis Acid/Base and understanding the relative strengths of acid/bases.

TimothyRags said:

Lewis Structures
Acid/Base Chemistry
Bases vs. Nucleophiles
Resonance
Stereoisomers
Steric Clashing
Electronegativity
Hydrogen Bonding
VSEPR Theory
Molecular Orbital Theory
Aromaticity
Ring strain
Learn how to draw in 3-d

When dealing with reactions, you are basically doing the same reaction (filled to empty orbital) over and over again.

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Good list.

Also, Elimination and Substitution mechanisms. Those were tested pretty hard in my Org. Chem I class.

Nomenclature too.

alexfoleyc said:

To me, all of it seems like endless memorization. But I know that it is critical understand the concepts.

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Great practice for your future. ;-)

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TimothyRags said:

Lewis Structures
Acid/Base Chemistry
Bases vs. Nucleophiles
Resonance
Stereoisomers
Steric Clashing
Electronegativity
Hydrogen Bonding
VSEPR Theory
Molecular Orbital Theory
Aromaticity
Ring strain
Learn how to draw in 3-d

When dealing with reactions, you are basically doing the same reaction (filled to empty orbital) over and over again.

Click to expand...

VSEPR and Molecular orbital theory? that wasn't even mentioned in EK i believe...

It is all about knowing where the electrons are, and how to push them. Learn to draw those arrows with meaning.

The above list of subjects is very comprehensive. however, from an even more basic standpoint, my strength in orgo came from being able to spatially visualize what was going on with the molecules. Once you're able to do this, the most common rule that explains why all the other theories work, is that most of the time, atoms and charges like to be as far apart from each other as possible (H-bonding and partial positive and negative attractions are important exceptions to this rule). For example, you can reason why the SN1/E1/SN2/E2 reactions proceed the way they do is because of how the molecule is shaped. A nucleophile will attack the electrophile (SN reaction), but only if there is the physical space for it to squeeze in there. If there is no space for this to occur (tri-substituted reactant), it will find some other way to react (E reaction). I am a very visual learner, so that's how I reasoned my way through orgo.

Also, learn what makes a molecule stable (resonance, neutralizing charges, aromaticity, etc), and what makes it reactive (charges, ring strain, "bad" sterics, etc). Reactions will always try to increase stability.

For me O-Chem was pretty easy, once you understood the some basic concepts and reaction types, nearly all of the reactions you learn will fit in several smaller categories, and once you realized that, the "memorization" becomes much easier.

For me what it boiled down to was what function group do it add, how does it add it (orientation and mech.).

Many of the mech. are very similar and there is almost always more than one way to add the same functional group.

jm192 said:

Lewis Structures

Acids/Bases


Electronegativity
Hydrogen Bonding
Resonance

Click to expand...

We learned all this in Gen Chem II, does it differ in Orgo? I start Orgo Monday and was just wondering.

Poliscidoc said:

We learned all this in Gen Chem II, does it differ in Orgo? I start Orgo Monday and was just wondering.

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They start going nuts with carbons. Generally in Gen Chem it is mostly inorganic compouds they have yuou drawing.

A solid grasp of organic really can help. In pharm the other day it was mentioned that a certain methyl group made a compound more nonpolar and was why it could cross the blood brain barrier when other drugs in its class could not. Course, one could just memorize that Drug D can cross when Drug Q can't, but I'd prefer to understand why.

After taking orgo 1, orgo 2, and advanced organic. I can tell you that orgo requires 95 % concept and 5 % memorization. You may feel its memorization now but it is very conceptual.

tack onto that list thermodynamics/kinetics

Poliscidoc said:

We learned all this in Gen Chem II, does it differ in Orgo? I start Orgo Monday and was just wondering.

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Everything makes sense in organic, as opposed to "memorize this" in g chem. It's refreshing

Want an A+? Memorize EVERYTHING. Don't pick and choose things to learn.

0kazak1 said:

For me O-Chem was pretty easy, once you understood the some basic concepts and reaction types, nearly all of the reactions you learn will fit in several smaller categories, and once you realized that, the "memorization" becomes much easier.

For me what it boiled down to was what function group do it add, how does it add it (orientation and mech.).

Many of the mech. are very similar and there is almost always more than one way to add the same functional group.

Click to expand...

.

I really, really hope that there is more to OChem than memorization as I will be taking it in summer. Pure memorization over 3 months would be equal to death.

SU1989 said:

I really, really hope that there is more to OChem than memorization as I will be taking it in summer. Pure memorization over 3 months would be equal to death.

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Someone a few weeks ago summed it up very succinctly: 1. Carbon forms 4 bonds. 2. Negative attacks positive. 3. Resonance = stability 4. weak conjugate base constitutes strong acid and vice versa.

I can't really top that for brevity , except that there should be something about sterics in there. Here's my top 5.

1. Nucleophile attacks electrophile.
2. The electronegativities of atoms generate a lot of the patterns - get to know the relative strengths of O, N, C, H, F, Cl, Br, I, S and it will help a lot.
3. Always be on the lookout for trends. I can't stress this enough. Look for trends. There are a lot of them. Underlying each trend is a key concept.
4. Like charges repel - every atom is surrounded by an electron cloud, and they adopt configurations that minimize the repulsions between these clouds.
5. Doing organic chemistry without knowing (and understanding) pKas is like playing poker without knowing the strengths of the hands.

This has nothing to do with organic chemistry, but just the fact that you are *asking* already puts you ahead of a lot of people. It's often the best students who ask the questions.

alexfoleyc said:

Thanks a lot buddy. That makes a lot more sense! Is that like the "big picture" of orgo?

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Not quite, I could go on - I didn't mention stereochemistry. But a whole bunch of other people did, so there you go.

4. weak conjugate base constitutes strong acid and vice versa.

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Not necessarily true

People overemphasize the memorization component of orgo, IMO. It is actually a very conceptual class. If you can get the concepts down, you can guess, fairly accurately, what a reaction is going to do -- even if you've never seen the reactants. I have done it on tests, so I know it can be done.

i thought it was mostly memorizing, especially w/ the reagents.. there were over 100+ reactions to remember for my exams and many of them have stuff like H2O, or OH-, or Heat or some random junk. I always forget which one has what and i end up losing points =(. then again, the mean score for orgo was always around a 40 so its okay i guess

The idea is that those 100 reactions can be grouped into maybe 8 types that all follow predictable patterns.