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!
Alkynes react with halogens in the same way as alkenes. The first addition of the halogen to the π bond produces a trans dihalide which is then converted into a tetrahalide: The trans dihalide can be prepared by … Read more
Alkynes have a general formula of CnH2n-2, and that is 4 H atoms less than alkanes, which have the general formula CnH2n+2. In between, we have the alkenes with the CnH2n formula. This means that alkynes can be reduced by … Read more
We have seen that in acid-catalyzed hydration of alkenes, an alcohol is formed according to the Markovnikov’s rule: In a similar way, alkynes also undergo acid-catalyzed hydration. The final product of this reaction, however, is a ketone: … Read more
We have seen that the electrophilic addition of hydrogen halides to alkenes produces alkyl halides according to Markovnikov’s rule: Alkynes undergo hydrohalogenation following a similar pattern. The addition of one equivalent of HX produces a vinyl halide, which … Read more
Alkynes are prepared by elimination of alkyl dihalides: The reaction goes by E2 mechanism and is similar to how alkenes are prepared. The difference here is that two halogen atoms are needed because the triple bond id formed by two … Read more
In the previous post, we talked about the acid-catalyzed hydration of alkenes where an alcohol is formed as the major organic product: If an alcohol, rather than water, is used as the solvent a very similar reaction takes … Read more
In the previous post, we talked about a simple strategy you can use for changing the position of a double bond. A similar tool-set, commonly used in organic synthesis, is the change of the position for a leaving group: … Read more
Changing the position of a double bond is a very important tool in organic synthesis. For example, let’s try to figure out what happens in this transformation: The double bond has suddenly moved to produce a new regioisomer … Read more
This is a comprehensive problem that covers the following topics and will serve as a review of all of them: Substitution and elimination reactions. Particularly, substitution and elimination reactions of alcohols, the regio– and stereochemistry of E2 reactions and E2 reaction … Read more
