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!
In the introductory post about electrophilic addition reactions to alkenes, we emphasized that they are electron-rich species because of the two extra electrons brought in by the π bond. This feature makes them the nucleophile, or Lewis base in a … Read more
Markovnikov’s rule is a general trend predicting that in the reactions of HX (HCl, HBr, HI) species with unsymmetrical alkenes, the X adds to the more substituted carbon of the double bond. The reason for this is the greater stability … Read more
At the beginning of this chapter, we learned that alkenes are electron-rich species and, therefore, undergo a variety of electrophilic addition reactions. To convert them to epoxides, we want to add an oxygen atom to a double bond. This oxygen … Read more
Diols are compounds containing two hydroxyl groups; therefore, we can view the conversion from alkenes to diols are adding two OH groups across the double bond. These are called dihydroxylation reactions: Notice that the two OH groups are … Read more
The addition reactions of water to alkenes (hydration of alkenes) can be viewed as adding an H and OH groups to the double bond. There are a few ways of achieving this, and the key difference is the regiochemical outcome … Read more
Why are they Called Addition Reactions? Let’s first understand why the reactions of alkenes are called addition reactions. The general formula of alkenes is CnH2n which is two hydrogens less than alkanes (CnH2n+2). This means alkanes are saturated as there … Read more
Halohydrins are compounds containing a vicinal (adjacent) halogen and a hydroxyl groups. Halohydrins are prepared by the traction of alkenes with halogens in the presence of water: Recall that in neutral solvents such as CCl4 and DCM, the … Read more
Addition of HBr, HCl, and HI to Alkenes The regiochemistry of regioselectivity of a reaction is the preferential formation of one out of two or more possible regioisomers. For example, when an unsymmetrical akene is reacted with a hydrohalic acid … Read more
Acid-Catalyzed Addition of Alcohols and Alkoxymercuration Alkenes can be converted to ethers by reacting them with alcohols in the presence of acid or using Hg(OAc)2 catalyst. You may wonder why use a toxic mercury catalyst if it … Read more
There are two main ways of converting alkenes to alcohols, and both are hydration reactions of alkenes. One is the acid-catalyzed hydration of alkenes, and the other is the hydroboration-oxidation of alkenes. An important difference between these methods is the … Read more
