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!
We have learned in the discussions about Grignard reagents that they must be used in dry conditions and aprotic solvents because the organometallics are strong bases and are quenched in any medium with acidic protons: So, if we … Read more
We have seen earlier that the length of carbohydrates can be enlarged by using the Kiliani-Fischer synthesis, where an aldose is converted into the next higher aldose by adding one carbon to the chain: The reverse, that is, … Read more
The oxidative cleavage of alkynes is typically achieved with ozonolysis or by reacting them with a basic or acidic solution of potassium permanganate (KMnO₄). For internal alkynes, the products of the reaction are a pair of carboxylic acids, and for … Read more
In the Wolff rearrangement, an α-diazocarbonyl compound is converted into a ketene by the loss of nitrogen, which is facilitated by a 1,2-shift (1,2-rearrangement): As a reminder, ketenes are highly reactive species that contain a C=C=O functional group: … Read more
The Structure of Ketenes Ketenes are compounds containing a C=C=O functional group: The structure and geometry of ketenes are similar to those of allenes, where three carbon atoms are connected via double bonds. As much as the central … Read more
The Arndt-Eistert reaction is used for extending the carbon chain of carboxylic acids by one carbon atom: The extra carbon is introduced via diazomethane (CH2N2), which is quite nucleophilic and, upon reacting with an acid chloride, forms a … Read more
We have seen that LiAlH4 is one of the most powerful reducing agents and can be used to reduce many functional groups, such as aldehydes, ketones, esters, nitriles, and even carboxylic acids. Many of these reductions can also be achieved … Read more
When learning about ortho, meta, and para substitution in electrophilic aromatic substitution, we have seen that the para position is generally preferred, especially when the activating group is bulky. For example, we can see how the ratio in favor of … Read more
Remember that when discussing crossed aldol reactions, we saw that they occur between two carbonyl compounds, one of which is first converted into a nucleophile through deprotonation at the α-position. The product is typically a β-hydroxy carbonyl compound, which can … Read more
One of the factors we learned about increasing the stability of resonance structures was the presence of heteroatoms next to carbocations due to the donation of the lone pair and forming a new resonance structure with a complete octet on … Read more
