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
Common features of E1 and E2 mechanisms Both E1 and E2 are elimination reactions with some common features. First, in both reactions, there is a loss of hydrogen and the leaving group, and the result is the formation of a … Read more
E1 reactions are regioselective and, just like in the E2 mechanism, the Zaitsev product predominates due to the higher stability of the more substituted alkene: Notice that in the reaction above, water was used as a weak base, … Read more
Check Also in Elimination Reactions: Elimination Reactions of Cyclohexanes General Features of Elimination The E2 Mechanism Regioselectivity of E2 Reactions: The Zaitsev and Hofmann Products Stereoselectivity of E2 Reactions Stereospecificity of E2 Reactions The E1 Mechanism Stereoselectivity of E1 Reactions … Read more
