So, it’s a few months to JEE and you’re still wondering how to master those nerve racking chemical reactions. Fret not. Here’s a digest to your rescue.
However, I would like to give you a fair warning that studying just a few chemical reactions won’t help and it is imperative that you have in depth knowledge of all topics. Before we go any further, I would highly recommend you study all NCERT Chemistry textbooks for Class 12. Also, the most fundamental in Reaction Chemistry are the following
- Intramolecular Reactions are faster than Intermolecular Reactions
- Reactions happen to form the stabler of all the possible products.
- Strong Acids react with the stronger base, of the available.
Here are a few more basic points you might want to visit.
Moreover, don’t try to rote learn chemistry, you’ll fail, miserably. It’s good if you study and revise inorganic and organic reactions regularly. For those planning to master the concepts now, try to make Godspeed.
While NCERT books are one of the best reference materials, once you’re done with those books, you can refer to a book called Reactions, Rearrangements and Reagents by S N Sanyal. It will come in very handy, to add on it is affordable-around Rs 100.
Now, for those of you who are crunched on time, and those losing patience, here is a list that will help you:
Reactions on Alkynes
- Darzen Condensation
The Darzens Reaction is the condensation of a carbonyl compound with an α-halo ester in the presence of a base to form an α,β-epoxy ester.
- Hydrolysis of Ketal to give Ketones
Addition of aqueous acid to acetals will transform them back into ketones (or aldehydes). This is often referred to as “deprotection” of ketones (or aldehydes).
- Micheal Addition
The 1,4-addition (or conjugate addition) of resonance-stabilized carbanions. The Michael Addition is thermodynamically controlled; the reaction donors are active methylenes such as malonates and nitroalkanes, and the acceptors are activated olefins such as α,β-unsaturated carbonyl compounds.
- Ozonolysis of Alkynes
Ozonolysis implies that ozone causes the alkyne to break (-lysis).Reagents used are ozone followed by a simple aqueous work-up.If the alkyne is terminal, i.e. contains R≡CH, then the products are RCO2H and CO2 since unstable carbonic acid, HOC(=O)OH, is produced.
- Nucleophilic Addition reactions
Nucleophilic addition reactions are an important class of reactions that allow the inter-conversion of C=O into a
range of important functional groups.
Reactions of Alcohols:
- Esterification: Reaction with acids to, form ester
When a carboxylic acid is treated with an alcohol and an acid catalyst, an ester is formed (along with water). This reaction is called the Fischer esterification.
- Substitution Reactions with alcohol: This reaction with Lucas Reagent is used for the qualitative test for the different types of alcohols.
Reactions of Aldehydes:
- Ozonolysis of alkenes
Ozonolysis allows the cleavage of alkene double bonds by reaction with ozone. Depending on the work up, different products may be isolated: reductive work-up gives either alcohols or carbonyl compounds, while oxidative work-up leads to carboxylic acids or ketones.
- Hydrolysis of Acetal to give Aldehydes
- Perkin Condensation
The Perkin reaction is an organic reaction developed by William Henry Perkin that is used to make cinnamic acids.
- Cannizzaro Reaction
This redox disproportionation of non-enolizable aldehydes to carboxylic acids and alcohols is conducted in concentrated base. α-Keto aldehydes give the product of an intramolecular disproportionation in excellent yields.
- Benzoin condensation
This reaction is used for the identification of benzaldehyde and benzilic acid
Tips while working on isomers:
- Cross check your answer because most isomer questions are trick questions.
- Check for cis-trans if double bond is given.
- Do not try to apply combinations to count the number of isomers. Silly mistakes are likely to happen.
I hope this gives you a good revision of special chemical reactions and also if your preparation is actually very good. All the best and may the force be with you!