Holy Shit, O.Chem

I took both semesters when I was a 19-20 yo kid and managed to get a B and C, but now I'm taking it years later and it's completely overwhelming.

I thought being a little older and a little wiser would serve me well, but it turns out the snot-nosed brat who was skipping all his classes to get drunk and get laid could still kick the 27 year old me version's ass at this stuff.

Why are there multiple right ways to solve a synthesis, but I always pick the wrong way? I'm new here so go easy on me because I'm not hip to these brainlet memes you guys have.

I'm just an average joe trying to get an honest pass on this class

Oh, and for the altruists out there if you know of any really great O.Chem resource materials that would be a big thanks.

Honestly, I'm talking to my professor and you can tell he wants to be able to give me a passing mark.

Reactions always proceed along pathways which minimize the Gibb's free energy at each step. If a reactant has the opportunity to drastically reduce its G, it will do so.

G=H-TS, where H is the energy required to undergo all the steps and TS represents the diversity of states the reactant might be in(such that only a fraction of these represent the reaction pathway

That picture you attached is way too complicated, you're not going to be able to memorize that in its current form

Organic chemistry was easy because it's pure memorisation. I don't get this meme.

Not in thermodynamic equilibrium, thats only true under kinetic control

learn how to do mechanisms, memorizing the reactions is harder if you cant figure out why they do what they do

In all, G represents the likelihood that a reactant will proceed along a given pathway. Look for pathways that don't require a lot of energy but also have some likelihood of occurring given random thermal motion(translation, stretching, twisting, bending, you name it).

Are you a premed student or something?

Only brainlets memorize O-Chem, once you get a solid grasp on electron density and resonance it's all relatively straight forward - especially for undergrad level courses.

You are quite wrong, Gibbs is used to calculate equilibrium in many thermodynamic systems. Delta H is what is minimized under kinetic control, or low temperatures. Reactants move toward states that are more energetically accessible but do not represent global G minima

Draw out the mechanisms and figure why the electrons move the way they do OP.

Well, you do need some memorization for the name reactions and it helps to know some general patterns by which reactions proceed and the reasons why these patterns are favoured
But yeah, with a deeper understanding, it's much less work

Masterorganicchem
Good resource from PhD chemist explaining o-chem in simpl-ish terms.

I would suggest learning some o-chem intuition as it could help you with memorization.
Keep in mind that it all is about bond strenght due to electronegativity differencial and stability due to electron density.

Learning about reactions which are Kinetics driven or Thermodynamically driven will help you a lot in understand some of the higher level reaction mechanisms.

Memorization vs. Understanding in O-chem is what usually what separates the pre-meds from the engineers/PhD students

>tfw taking ochem this semester and prof allows open notes on tests
plus no homework, and he's one of the best, most comfortable lecturers i've ever had. i have a pretty wicked mancrush on him

Pic made me lose

Is there any way you could show me some of his exams? Because either that class is easy as shit or he has some really great exam questions

it's a little from column a, a little from column b. questions tend to have both a practical part and a conceptual part with multiple parts, or joining multiple ideas-draw it out and explain what's going on.

There's multiple ways to solve a synthesis because that's just how O chem works. In general, the more robust the reactions you use, and the shorter the synthetic pathway will give you a better overall synthesis irl.

If you want to get better at O chem, learning and practising mechanisms is the way to do it. Most reactions are just several steps of standard mechanisms. pKa values are very good at guiding you through mechanisms - e.g. why does an acyl chloride react with an alcohol to form an ester, but a chloride ion will not react with an ester to form an acyl chloride? The key is in pKa's - chloride has a much lower pKa (and is thus a more stable leaving group) than an alkoxide (which is between 16-19 usually). Molecules will almost always expel the more stable leaving group if it has the option to do so.

Don't try and memorise the steps of each reaction, there's way too many reactions in O chem for that to be a sustainable method.

A good resource for learning mechanisms. It's like 10 bucks on amazon. Well worth.