Organic II help!!

[Ash2021]

Does anyone know of any good tutoring websites or books? I am struggling in my Organic II class, but I am really having a hard time with synthesis problems and mechanisms. How do you even began to complete a synthesis? On my exam we have a starting material and a product, and it is usually 7 steps long or more. There is usually a given structure every three steps, not including the 7.

So, if anyone has any good tips, tutoring/textbook suggestions, I would really appreciate it.

Also, my university does not offer tutoring for organic chemistry.

 

[FinallyOnTrack]

Oh man, I loved organic 2! Organic 1 can go kick some rocks... lol

The best thing I would recommend to you is learn the reaction mechanisms forwards and backwards..

Draw a diagram with something in the middle then react it with each RXN mech - once you have ~5 new compounds do a reverse of t to get back to the original - then take the new compounds and react them again..

Wash, rinse, and repeat over and over until you get a full sheet of reactions...

You page should look something like this:

http://leah4sci.com/wp-content/uploads/2013/11/reaction-map-rv-feb-21-2018.pdf

Now that you have a quick reference sheet (and it’s fresh on your mind)

To practice some synthesis problems:

Take any 4 carbon alcohol and react it to make X, Y, and Z compounds..

Hope that helps you some..


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[FinallyOnTrack]

Also, I forgot to mention (but I’m sure you already know this) - with each reaction some of the product is lost.. so if you can compete the synthesis in 3 steps, you’ll have more product than with 7 steps..

Remember that for each reaction you have a major product and a minor product - knowing how each RXN mech works will help you greatly..

Note cards are your best friend!

Good luck 😀


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[NextStepTutor_4]

@FinallyOnTrack has some really good advice about repetition to get reaction mechanisms down.

At the end of the day, it's all about electrons. In the past, it's helped me to understand the basics first: for example, a carbonyl bond is basically a huge dipole, suctioning electrons towards that electronegative oxygen. Now the carbon is almost completely robbed of electrons (electrophile), and is prime for attack by an electron-rich nucleophile. You'll see patterns like this over and over again. For example, you can take almost any reaction in that reaction map
@FinallyOnTrack attached and try to predict where the electrons want to be. This helps explains things like the fact that electronegative atoms like Cl make acids stronger by stabilizing the electrons / negative charge when the acid donates an H+. It also explains why some groups are added at the more substituted position, and some at the less substituted position, depending on which is better equipped to handle excess positive charge as an intermediate.

Something else really common you'll encounter is redox. Your weak oxidant is PCC (an alcohol can gain just ONE more oxygen bond), and all those chromium-containing oxidants are strong oxidants, which can oxidize all the way to a carboxylic acid. Your reducing agents have lots of hydrogens (LiAlH4, NaBH4), so when you see them, remember that hydrogens are just protons, so they'll be looking perhaps for some electron-rich double bonds to disrupt where they can add in a few bonds to hydrogen.

I definitely second the idea of creating flashcards. What has helped me is to right out very general schematics like "ROH + ROH -->" on the front and "ROR + H2O" on the back so that no matter what alcohols or ethers you're given, you'll be able to predict the reaction like a pro.

 

[pharmD2022]

I took the PCAT before I took organic chemistry and basically had to teach it to myself. So I used Khan Academy to review orgo and it was amazing! I'm not sure which topics your orgo II class focuses on but there's pretty much a KA video for everything orgo related. I'd look into it, they explain and give you practice problems.