The dehydrohalogenation of alkyl halides gives alkenes. For example, we can react alkyl halides with strong bulky and non-bulky bases to prepare the Zaitsev or Hofmann alkene: Preparation of Alkynes As the name suggests, in these dehydration reactions, … Read more
Alkyl halides can be converted to alkenes via elimination reactions using strong and weak bases. These conversions are also known as dehydrohalogenation reactions: The elimination reactions are most often achieved by using strong bases, and there are several … Read more
Ring Strain and Ring Expansion The title of today’s discussion contains two keywords: Ring Expansion and Rearrangement. So, what are those? A ring expansion is the transformation of a smaller ring to a larger ring. A rearrangement is a change … Read more
When a beta hydroxy carbonyl compound is treated with a moderately strong base, such as a hydroxide or an alkoxide, an elimination occurs by expelling the hydroxyl group. The most common example is the aldol condensation reaction: So, … Read more
In simple words, the Hammond postulate predicts whether the transition state resembles the reactant or the product of the reaction. According to it, the transition state resembles the structure of the species (reactant, intermediate, or product), which is closer to … Read more
In the previous post, we talked about the Hofmann reaction where amines are converted into quaternary ammonium salts and later to alkenes. Remember, amines, and especially the conjugate bases of amines, are strong bases and therefore, they are poor leaving … Read more
Amines can participate in E2 reactions to form alkenes. However, just like the OH group of alcohols, the NH2, or any other amino group, is a quite strong base and needs to be first converted into a good leaving group. … Read more
We have seen earlier how alkyl halides undergo E1 and E2 elimination reactions to form alkenes: In those reactions, the leaving group was the halide, which was kicked out by removing the β-hydrogen and making a new π … Read more
Choosing Between SN1, SN2, E1, and E2 If you are reading this post, welcome to the world of SN1, SN2, E1, and E2 business! The good news is that you are not alone and that also, we are going to make … Read more
In this practice problem, you will need to determine the major organic product and the mechanism of each reaction. This covers the competition between SN1, SN2 nucleophilic substitution, and E1/E2 elimination reactions. You can check this post (SN1 SN2 E1 … Read more
