The only way of mastering any topic in Organic Chemistry is doing lots of practice problems. And I know, seeing my students, that starting to work on a practice problem may be the hardest part as you don’t know where to start. It is difficult to visualize what where the double bond would be moved if you follow the five curved arrows crammed in one step. Here is the trick:
We are always told to think before doing something. Fair enough. But let me tell you, it is also strangely enough, that in Organic Chemistry, it is often better to draw and then think about what you did (not in the lab though). It is much easier to have a structure in front of you and check for errors and improvements.
Do the first step, take the pencil and you will see that the ball gets rolling.
You have all these Organic Chemistry Practice Problems waiting to be solved!
The number of NMR signals represents the number of different types of protons in a molecule. This is the example we used in the introduction to NMR spectroscopy: The spectrum has five signals which indicates five types of … Read more
We have seen that chemically equivalent protons give one signal in NMR spectroscopy. For example, How many signals do you expect to see in the 1H NMR of ethane? Despite having 6 hydrogens, it only shows one signal, and this … Read more
In the previous post, we talked about the principles behind the chemical shift addressing questions like how the ppm values are calculated, why they are independent of the magnetic field strength, and what is the benefit of using a more … Read more
Here is the basic principle of NMR spectroscopy: we put the sample in a magnetic field the nuclei distribute in two different energy levels – some oriented with the applied field (lower in energy – ɑ Spin state) and some … Read more
NMR spectroscopy is the most common and comprehensive technique for studying the structure of organic molecules. In a broad sense, it still works by the same principle as other spectroscopies, and that is the interaction of the molecule with certain … Read more
We have seen that most reactions of aromatic compounds involve electrophilic substitutions because the π electrons make the aromatic ring electron-rich and therefore, nucleophilic. However, some aryl halides with a strong electron-withdrawing substituent(s) on the ring can undergo nucleophilic substitution … Read more
In the previous post, we talked about the lack of reactivity of benzene towards bromination and the Kekulé structure that was suggested to explain these unique features. In short, Kekulé suggested that benzene is an equilibrium mixture of two compounds … Read more
The addition of cyanide ion to the carbonyl group is another common reaction of aldehydes and ketones. The product of these reactions is a cyanohydrin. It works in a slightly basic conditions since the HNC itself does not dissociate much … Read more
Let’s talk about the Wittig reaction, which is used for converting aldehydes and ketones to alkenes: So, this is, in a way, the reverse reaction of the alkene ozonolysis, where the C=C bonds were cleaved to form carbonyl … Read more
Imines and enamines can be hydrolyzed to aldehydes and ketones in acidic conditions: Remember, the reactions of aldehydes and ketones with alcohols and amines are all reversible, and therefore, the products of these reactions – acetals, imines, and … Read more
