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!
From the basics of valence bond theory and chemical bonding, we know that covalent bonds are formed by an overlap of atomic or hybrid orbitals. Let’s just collectively call them orbitals. So covalent bonds are formed by an overlap of … Read more
Diazomethane is a quite interesting compound that is used in many synthetic transformations. So, before going over these reactions, let’s draw the structure of diazomethane by showing the corresponding resonance structures: The main theme that gives the characteristic … Read more
Oximes are compounds containing a C=N-OH functional group. They are prepared by a condensation reaction of aldehydes or ketones with hydroxylamine under mildly acidic conditions. The reaction starts with a nucleophilic addition of hydroxylamine to the carbonyl group, which forms … Read more
Organolithiums are extremely good nucleophiles and strong bases, and it should not be a surprise that they readily react with epoxides, which are highly strained electrophiles. The nucleophilic attack of the organolithium opens the epoxide ring, forming an alkoxide ion, which, … Read more
One of the first reactions of Grignard reagents we learn is the one with aldehydes and ketones, where secondary and tertiary alcohols are formed: These are classic examples of nucleophilic addition reactions to carbonyl compounds, and the good … Read more
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
