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How to study for organic chemistry?

How to study for organic chemistry?

 

How to study for organic chemistry? I get asked this question pretty frequently…and while there is no easy answer (because every student is different), here is the four-pronged solution that we have come up with here.  This answer is based on a survey of organic chemistry professors that we conducted a while back.  They told us the best ways to study and the ways to avoid.  If you are interested in looking at the results of the entire survey, you can find them here—> how to pass organic chemistry (or even get an A).  We will summarize it for you here though.  It is actually pretty simple.

Situation: the organic chemistry is coming soon.  Too soon!  Not nearly enough studying has been done yet.

Step 1: Watch some organic chemistry review videos. It is really helpful to hear someone else teach the material in a little bit different way, and review videos will condense the material down for you. Here are our favorites organic chemistry videos (which happen to be ours)

Step 2: Work practice tests and practice problems. Over 90% of the professors we surveyed said this was the best way to learn organic chemistry. There are organic chemistry test banks out there (see organic chemistry test bank) that will work wonders for you.

Step 3: Find some good flashcards and practice non-stop with those. If you can’t find decent ones, make your own and emphasize the topics you didn’t do well with in step 2.  Good old fashioned 3’x5′ index cards work great.  Making them will help you learn the material even better.

Step 4: If you can, learn the material rather than memorizing it.  Organic chemistry is a discipline that requiring understanding…HOWEVER if you are pressed for time, then just memorize the heck out of it now and then go back and LEARN it before the final exam.

Hope this was helpful.  Obviously learning a complex subject like organic chemistry is more difficult than just four easy steps, but if you study hard it will go just fine.

 

free organic chem study guide

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86 Tricks To Ace Organic Chemistry – Multimedia Edition is now available for the iPad

AceOrganicChem.com is very proud to announce the release of it’s best-selling book, 86 Tricks To Ace Organic Chemistry, as an iPad multimedia book. In addition to the material that made the previous version a must-read, it now also contains videos, flash cards and practice problems, making it an instant hit. It is quite a wonder and a must see on the iPad.

http://itunes.apple.com/us/book/organic-chemistry-86-tricks/id507347523?mt=11&ls=1

Now available in the iBookstore for only $7.99, it really is something to see.

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Organic chemistry help: free iPhone app

Hey everybody. So there is a free organic chemistry app for the iPod/iPhone in the iTunes app store. It is called “Organic Chemistry Essentials” and it rocks. There are over 15 different sections to help with organic 1 and 2 classes and even has a section of nerd humor.

As of today, it was downloaded over 40,000 times and has a 4.5 star rating. We highly recommend this. Give a try, it is free so you have nothing to lose.

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Organic Chemistry Help: “Eject! Eject! Eject!” Carbonyls with an ejectable group are added to twice.

These functional groups remind me of 1985 when Maverick flew through the jet wash and Goose and he had to eject from their F-14 Tomcat.  What does this title mean?  What we are trying to say is that carbonyls can be classified two different ways: ejectable or non-ejectable.  What this means is that sometime when a carbonyl is attacked by a nucleophile the carbonyl will eject one of its substituents before it reduces the carbonyl to an alcohol.  After the group has been ejected, then a second equivalent of nucleophile will reduce the carbonyl to alcohol.

In essence, this means if a carbonyl has an ejectable group on it, a nucleophile will add twice to that carbonyl.  Some examples of ejectable and non-ejectable systems are below:

In terms of synthesis, we will then observe the following:

As shown above with the ketone and the aldehyde (which have non-ejectable substituents), the Grignard reagent can only add once to the carbonyl, giving an alcohol as the product in both instances.  However, in the case of the acid halide and ester (which have ejectable groups attached) the first equivalent of Grignard kicks off the ejectable group to give a ketone.  This ketone can then be reacted with another equivalent of Grignard reagent to give the final product, which is a tertiary alcohol.   In the example above, we have added two equivalents of Grignard to the starting material in two different steps.  However, if the alcohol is your desired end-product, you can do this all in one step by adding two or more equivalents of Grignard reagent.

Take Home Message: Nucleophiles will substitute twice at the carbonyl if the starting material is an acid halide or an ester.

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Free Organic Chemistry App for iPhone/iPod Touch

Hi everybody, so AceOrganicChem.com has teamed up with an iPod developer and has released an app to give a little on-the-go aide in organic chemistry.  The app is called “Organic Chemistry Essentials”, the rating so far is 4.5/5 stars from users, and is free. 

It has 10-15 sections and gives tricks and tips to nail organic chemistry.  It is a great app, and best of all it is free.  I strongly recommend it.    Link is organic chemistry app

Here is one review on it: “Simply laid out, but it is very helpful, and the humor (both within the lesson and on its own) provide compic relief along with helping the reader to remember.  Very fun”

As always, for help with all of organic chemistry, please go to organic chemistry

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Organic Chemistry Help: Fischer Projections are a Black Tie Affair

Emil Fischer is considered by many to be the greatest organic chemist to ever live.  His problem was that he created a way of looking at organic molecules that is very confusing to undergraduates.  These structures are necessary to learn and are very helpful when looking at certain molecules (such as carbohydrates), but they are also very easy to jumble.  This is because Fischer structures are drawn as crosses, which could lead one to erroneously think that the central carbon is flat, when it is actually still tetrahedral.

The easiest way to look at these is to think of them as bowties that have been strung together:

3-dimensionally speaking, the substituents that are on the sides of the structure are depicted at the end of the bowtie and are represented as “coming out of the paper”.  The backbone is composed of dashed lines, which are meant to represent that those portions “are going into the paper”.  This is now a much easier way to view these structures, as it is more apparent what area each substituent occupies.

The useful part of the bowtie projection is that it is now easier to assess the stereochemistry at each chiral center.   It should be much easier to visualize that the bottom chiral center is “R”.  This was not as obvious when viewing the Fischer projection as a cross

For more help like this, please go to organic chemistry

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The Good, The Bad and The Ugly of Summer Organic chemistry classes

Congrats on getting done with your finals!  Not an easy task sometimes.  But on the topic of today’s post, I was recently asked what I thought about students taking o-chem classes over the summer.  This is not an easy “yes or no” question, and definitely depends on the student.  Here are some of the considerations:

The Good:

1. It is only usually 5 weeks long. 

2. If you are not working this summer, it is much better than just sitting around doing nothing.

3. If you are not majoring in chemistry and don’t want to go to med school, it is a great way to get it out of the way quickly.

 The Bad:

1. If you ARE majoring in chem, it is very easy to forget everything that you learned in the class because you crammed it all into 5 weeks.

2. Classes are usually at least 3 hours per day, plus homework every night and an exam once a week.  This can be overwhelming.

The Ugly:

1. If you get a bad prof, keep the hemlock close.

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Organic Chemistry Help: Symmetric diols came from the Pinacol reaction

Some of your professors will try to sneak this one in on you during an exam:  Your professor will ask you to synthesize the symmetric diol shown below and you will either not know how or you will come up with a convoluted, difficult or wrong answer. 

While not obvious, there is a very simple way to create a symmetric diol using the Pinacol reaction.  Using a number of reducing agents, ketones and aldehydes can be coupled with themselves to form a symmetric diol, as shown below:

 

The reaction is also called the Pinacol Coupling Reaction and can be used on most aldehydes and ketones, but not on acid halides or carboxylic acids.  Now to address the original synthetic problem above:

 

The first step is reaction of the reaction of ethyl lithium with ethanal to form 2-butanol.  This is then oxidized to 2-butanone using Jones’ oxidation.  Now, under Pinacol Coupling conditions, 2-butanone is then reacted with itself using magnesium to form the final product. 

Take Home Message:  Symmetric 1,2 diols came from the Pinacol reaction.           

 

For more organic chemistry help, go to organic chemistry

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Organic Chemistry Help: Carbonyls are added to twice when they have an “ejectable” group on it

These functional groups remind me of 1985 when Maverick flew through the jet wash and Goose and he had to eject from their F-14 Tomcat.  What does this title mean?  What we are trying to say is that carbonyls can be classified two different ways: ejectable or non-ejectable.  What this means is that sometime when a carbonyl is attacked by a nucleophile the carbonyl will eject one of its substituents before it reduces the carbonyl to an alcohol.  After the group has been ejected, then a second equivalent of nucleophile will reduce the carbonyl to alcohol.

In essence, this means if a carbonyl has an ejectable group on it, a nucleophile will add twice to that carbonyl.  Some examples of ejectable and non-ejectable systems are below:

Some useful examples of this can be found in your textbook. But for more information on this, please see organic chemistry

Thanks alot, and as always, happy reacting.

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Organic Chemistry: There are only FOUR important IR peaks….that’s IT

Amazingly enough, IR is not used much by professional organic chemists.  This is because all IR can show is different functional groups.  Thus, IR cannot tell the difference between any of the molecules shown below:

All of the molecules above will show an OH peak and various C-H stretches, but each spectra will look striking similar.  Hence, we should recognize the limits of the instrument and not try to use it for more than it is intended.  Further, there are really only four peaks in an IR that we look for to tell us something about our unknown molecule.  Here, we show them in order of importance.

1)           Carbonyl peak (1750-1650cm-1):  This will be a very sharp, prominent peak and shows that a carbonyl is present in somewhere in your unknown molecule.  What is less obvious is which type of carbonyl it is.  It is not as easy to distinguish between ketones, esters, aldehydes, ect.

2)           OH peak (3500-3200cm-1): This is a large, broad stretch which cannot be mistaken for any other functionality.  One problem to be aware of is that the OH of water will also show up here, in the event that your unknown is not totally dry.  Remember, that this can be from an alcohol OH or a carboxylic acid OH.

3)           C-O peak (1300-1040cm-1): Usually a large, sharp peak, this can be from an alcohol, carboxylic acid, ether, or an ester.

4)           Nitriles (2250-2230cm-1) and alkynes (2100-2280cm-1) peaks: Usually rather small peaks, but easy to spot as they are the only peaks in that area.

For more help with this and other organic chemistry topics, please go to organic chemistry

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