orgo i synthesis help!

[dipbk]

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hi all,

i just had my orgo i final yesterday and bombed it. does anyone have suggestions of books or websites with synthesis problems that i might try over winter break?

thanks!

 

[aglo123]

Khanacademy.com goto browse>Science>Organic Chemistry

What I found to be very helpful (I got an A in OChem 1 this semester) was putting every reaction that I had no idea on, on a flash card.

I made three separate sets of flashcards,

as an example
Flashcard 1:
Front: ? + H2/Pd-C (1 eq) ----> alkene
Back: alkyne

Flashcard 2:
front: alkyne + ? ---> alkene
back: H2/Pd-C(1 eq.)

Flashcard 3:
front: alkyne + H2/Pd-C(1 eq.) ---> ?
back: alkene

I did this for every reaction I could not memorize off the top of my head, and it worked. I used up probably 300 flashcards and many hours of my time doing this, but I scored 50 points over the average on my final and got an A.

This "flashcard chemistry" allowed me not to have to focus on the reaction portion of the exams and really allowed me to maximize the points and my focus on the conceptual side of things like the IR/NMR and IMF questions where a lot of points can be lost because one does not divulge deep enough into the analysis.

 

[sLaughter]

Flashcard method really worked for me as well. I recommend talking it out with others on the whiteboard, too. Professors are good others with whom to try and talk it out, by the way!

 

[LightAtTheEnd]

You've probably heard of Khan Academy, but hardly anyone has heard of freelanceteach (youtube). He is 10x better than Khan Academy (for orgo, at least) because his videos are organized according to topic and he gives TONS of examples. Although I don't condone it, I did not attend a single one of my Orgo lectures (disliked the professor's way of teaching) and instead, watched his videos to study for tests. Easily made an A.

 

[jram2323]

da??? with glasses that==========me).

 

[487806]

hi all,

i just had my orgo i final yesterday and bombed it. does anyone have suggestions of books or websites with synthesis problems that i might try over winter break?

thanks!

Organic Chemistry as a Second Language book is good. I didn't use it because my textbook (Wade 7th edition) was great and really helped in solving those complex synthesis problems.

 

[kyamh]

Also, work from the back of the synthesis, it's often easier.

Another thought is to remember the fact that most synthesis problems can get a lot of partial credit. If you know what a part of the synthesis ought to be then put it down. If you can't remember how to get from the beginning to where you know stuff or from where you know stuff to the end, it's okay to just put a blank arrow - at least you will get credit for what you know.

Third piece of advice. Don't stare at the problem too long, start writing, it's a lot faster to see if you are on the right track if you try and draw out your idea than if you just try to think through it. Nothing wrong with crossing things out and starting over.

Edit: 4th advice: look through the rest of your exam for ideas about what to use in your synthesis. Sometimes you know a reaction well and solved a predict the products or whatever problem early on but then you completely forget about that reaction when your get to the synthesis part.

 

[deleted545787]

Organic chemistry by David Klein, excellent textbook. Easy to understand. Questions in it are too easy though IMO

 

[itsthat1guy]

Khanacademy.com goto browse>Science>Organic Chemistry

What I found to be very helpful (I got an A in OChem 1 this semester) was putting every reaction that I had no idea on, on a flash card.

I made three separate sets of flashcards,

as an example
Flashcard 1:
Front: ? + H2/Pd-C (1 eq) ----> alkene
Back: alkyne

Flashcard 2:
front: alkyne + ? ---> alkene
back: H2/Pd-C(1 eq.)

Flashcard 3:
front: alkyne + H2/Pd-C(1 eq.) ---> ?
back: alkene

I did this for every reaction I could not memorize off the top of my head, and it worked. I used up probably 300 flashcards and many hours of my time doing this, but I scored 50 points over the average on my final and got an A.

This "flashcard chemistry" allowed me not to have to focus on the reaction portion of the exams and really allowed me to maximize the points and my focus on the conceptual side of things like the IR/NMR and IMF questions where a lot of points can be lost because one does not divulge deep enough into the analysis.

My suggestion is to do the opposite of this, duo not memorize for organic chem.understand why a reaction proceeds the way out does and you will thank yourself in the long run.and do a lot of practice problems

 

[xbowers003]

david klein-organic chem as a second language. Excellent book. Also, youtube videos from thus nerdy dude with glasses that writes on a green chalkboard (forgot the name).

This

 

[Ossyaris]

I highly suggest Organic Chemistry by Francis A. Carey & Robert M. Giuliano and the solutions manual for the textbook. It's also an easy to ready textbook with somewhat difficult problems in it.

The way I studied for Orgo I & II wasn't by flashcards, but by understanding what's going on in the reactions and redoing synthesis questions over and over again. As for mechanisms, I just straight up memorized those.

 

[rolliespring]

Before you approach a synthesis problem, make sure you understand all the reactions that proceed to it COLD. You should be able to recognize the product immediately when given a single reaction. Do as many single reactions as possible. Synthesis was basically cake for me because I knew all the single reactions too well. I think the key is being able to recognize certain functional groups and substituents and know what reactions will result in them. Try to work your way backwards. If you get stuck then try to work forwards, usually you will arrive at the point where everything joins together.

Also, work from the back of the synthesis, it's often easier.

Another thought is to remember the fact that most synthesis problems can get a lot of partial credit. If you know what a part of the synthesis ought to be then put it down. If you can't remember how to get from the beginning to where you know stuff or from where you know stuff to the end, it's okay to just put a blank arrow - at least you will get credit for what you know.

Third piece of advice. Don't stare at the problem too long, start writing, it's a lot faster to see if you are on the right track if you try and draw out your idea than if you just try to think through it. Nothing wrong with crossing things out and starting over.

Edit: 4th advice: look through the rest of your exam for ideas about what to use in your synthesis. Sometimes you know a reaction well and solved a predict the products or whatever problem early on but then you completely forget about that reaction when your get to the synthesis part.

This.

 

[dipbk]

Thanks, guys. Really appreciate it.
Another naïve q: Synthesis does come up repeatedly through the entirety of orgo 2, as well, right?

 

[Med_Fit]

ABOVE ALL ELSE: Memorize the reactions... if you haven't practiced & memorized each rxn, synthesis is NOT going to happen... no matter how long you stare at those skeletons...

On another note, I think organic synthesis was the best part of orgo. It is like a big puzzle! Sure it takes time and a good conceptual mind but GET THOSE REACTIONS DOWN! NOTECARDS FTW

 

[musicalfeet]

I just finished orgo I..I think personally what really helped me a lot was really "memorizing" the mechanisms for each reaction. I use quotations because I didn't actively memorize it, I mostly thought what the reactants and reagents would PREFER to do with each other when combined. Each reaction sort of tells a story....

a dumb example of mine would be like:

Sn2: Extra pair of electrons! Negative charge attacks big molecule and kicks off the leaving group! It'll come kick it off from the back side! Invert Stereochem! Product achieved!

 

[aglo123]

My suggestion is to do the opposite of this, duo not memorize for organic chem.understand why a reaction proceeds the way out does and you will thank yourself in the long run.and do a lot of practice problems

Do this as well as what I suggested. But like I said I got an A in ochem, so take my advice if you want, it obviously worked for me.

 

[BlackBox]

hi all,

i just had my orgo i final yesterday and bombed it. does anyone have suggestions of books or websites with synthesis problems that i might try over winter break?

thanks!

If you can't write the reaction on a whiteboard at any time, off the top of your head, you don't know it.

I used to rewrite every reaction in an order, again, and again, until it felt like breathing. Unfortunately, I regularly forget to breath these days. 😉
GL

 

[Jabawocky]

hi all,

i just had my orgo i final yesterday and bombed it. does anyone have suggestions of books or websites with synthesis problems that i might try over winter break?

thanks!

Definitely KahnAcademy.com or Youtube. They both provide great video explanations and for youtube all you have to do is type in the type of problem you are working on and I'm sure there are 10 different videos explaining it.

Good Luck!

 

[deleted407021]

Each reaction uses similar but crucially different reagents and they each produce different types of products. The names for each should give you a clue as to what species are being reacted, however the actual mechanisms are going to need to be (I hate this word) memorized. Read the chapters for the elimination, substitution and radicalization mechanisms and the conditions for each.