First let’s quickly review free radical halogenation:

CH3CH2CH3 + Br2 (in the presence of heat or light) –> CH3CHBrCH3

Depicted here is free radical bromonation (the halogen here is Br). However, this can also be accomplished with Cl or I
There are three steps to the mechanism in this reaction: Initiation, Propogation, Termination.
Free radical stability follows carbocation stability allylic > tertiary > secondary > primary > methyl. Therefore this reaction will want to form the most stable free radical during the propogation step and thus the halogen will appear in the more substituted position. For example, in this reaction, the Br appears on the most substituted carbon in the product.

Free radical bromonation is a slower reaction and depends on the stability of the free radical intermediate.

Free radical chloronation is a more rapid reaction and depends not on the stability of the free radical intermediate, but rather on the number of hydrogens present. Therefore, an unreliable mixture of products tends to be formed with free radical chloronation.

We are often asked- why is Organic Chemistry so important?

Colleges, universities, medical schools and other health professional graduate schools would like you to believe that it is an important discipline relevant to the course of study you have chosen. The truth is that for most careers for which organic chemistry is a pre-requisite course, it is not the most crucial subject to have mastered in order to excel at your desired profession. It is no secret that organic chemistry is challenging. The real reason why it is so vital is because it is often used as a metric that admission committees use to differentiate between candidates. For one reason or another, it is notorious for being that course that “weeds out” the weakest students and highlights those who graduate schools feel are most likely to succeed.

Most likely because it is the course that most elegantly combines the challenge of needing to commit a vast amount of knowledge to memory while then being able to apply it in a variety of unique situations. This requires you to truly understand the material in order to effectively apply your understanding to new scenarios.

So focus on not just learning organic chemistry, but truly understanding it. That way it becomes second nature and can be applied to difficult synthesis reaction problems that you may not have seen before. Go ahead! Excel and you will prove that you are ready to face the challenges that lie ahead in your desired field!

Preparing for Exams
We get a lot of questions about the right way to prepare for Organic Chemistry Exams that test a lot of reactions. Just like anything else, succeeding in this course takes time and patience and perseverance. Its almost like running a marathon- you need stamina and you need to pace yourself. You can not learn organic chemistry overnight and you cannot run 22 miles in 3 minutes.

So let’s review some study tips:

1. Get a clear idea of what examination content you will be test on. It would be a shame to study something you aren’t tested on.
2. Try to find out the ways in which you will be asked tested.Example: Fill in the blanks in reactions, multi-step synthesis problems, drawing out mechanisms, comparing and contrasting different reactions etc…
3. Make a game plan, figure out how much time you have to study then plan our your study timeline. Here is a sample plan for two weeks prior to an exam or midterm:Days 1-5: Review the content and spend time learning the basics. Read your course’s assigned textbook.Days 6-12: Begin memorizing and committing the details to memory, learn the ins and out of the material, learn reactions backwards and forwards and how they relate to one another. Use the StudyOrgo.com Reaction Pages and Organic Chemistry Study Charts to test yourself and gain insight on help hints and tips for each reaction. Use the StudyOrgo.com Reaction Roadmap to understand the intricate interrelationship of the reactions you will be tested on.Days 12-14: Review and test yourself
4. When you study something, make sure that you know not just how to recognize it but how to draw it out yourself. For example, you should know how to draw out the reactants, reagents and products on paper. Use the StudyOrgo.com organic chemistry flashcards, cover two elements then draw out the third on paper.
5. Practice, practice, practice. Run through the flashcards many times, and try to come up with your own examples of each reaction
6. While many questions are centered around organic chemistry reactions, other exams test other concepts and ideas aside of reactions. Make sure you study everything you need to know!

Hey students,

Happy holidays and we hope you aren’t studying too hard over the holiday break.   We have gotten some great feedback from the students who used our system in the fall semester and we look forward to allow our methods to help those in the spring of 2012.  We are extremely excited to hear you have aced your exams and didn’t get too stressed out from one of the most dreaded courses for all majors.