is an α,β-Unsaturated ester CH2=CHCO2Et more or less reactive than an CH2=CHOEt in electrophilic addition and where do the two slot into the reactivity order of
CH2=CH2 < CH2=CHMe < CH2=CHBr
i think CH2=CHOEt is more reactive than the Br equivalent but im not sure if im right
please help
ch2=ch-ch2-ch2-ch2-ch3
To determine the relative reactivity of an α,β-unsaturated ester (CH2=CHCO2Et) and an aldehyde (CH2=CHOEt) in electrophilic addition, we need to consider the electron-withdrawing nature of the substituents present in each compound.
The α,β-unsaturated ester (CH2=CHCO2Et) contains an ester group (-CO2Et) that is electron-withdrawing due to the presence of the carbonyl group. This electron-withdrawing effect increases the overall reactivity of the double bond towards electrophilic addition.
On the other hand, the aldehyde (CH2=CHOEt) contains an aldehyde group (-CHO) that is also electron-withdrawing, but it is usually less electron-withdrawing compared to the ester group. Hence, the reactivity of the aldehyde towards electrophilic addition is typically lower compared to the α,β-unsaturated ester.
Regarding the reactivity order of the compounds in the example you provided (CH2=CH2 < CH2=CHMe < CH2=CHBr), we can say that the α,β-unsaturated ester (CH2=CHCO2Et) is more reactive than CH2=CHBr since the ester group is more electron-withdrawing than the bromine atom. However, as the reactivity order of CH2=CHMe (CH2=CHCO2Me) and CH2=CHOEt cannot be determined solely by the information provided, further analysis of the substituents is necessary.
Therefore, we can conclude that the α,β-unsaturated ester (CH2=CHCO2Et) is generally more reactive than the aldehyde (CH2=CHOEt), but the exact reactivity order within the given examples cannot be determined without additional information.
To determine the relative reactivity of the compounds, it is important to consider the electron-donating or electron-withdrawing effects of the substituents. In this case, we have an α,β-unsaturated ester (CH2=CHCO2Et) and an aldehyde (CH2=CHOEt).
In electrophilic addition reactions, the reactivity generally depends on the stability of the carbocation intermediate formed during the reaction. Electron-donating groups on the double bond stabilize the positive charge, making the compound more reactive.
In the case of α,β-unsaturated ester (CH2=CHCO2Et), the ethyl group (Et) attached to the carbonyl group donates electrons toward the double bond, which makes the α,β-unsaturated ester less reactive compared to a simple alkene (CH2=CH2) due to the electron-withdrawing effect of the carbonyl group. Therefore, it is expected to be less reactive than CH2=CH2.
On the other hand, the aldehyde (CH2=CHOEt) has a hydrogen atom directly attached to the carbonyl group, which acts as an electron-donating group. This electron donation stabilizes any positive charge, resulting in increased reactivity compared to CH2=CHCO2Et.
Now, comparing the reactivity order of the given compounds (CH2=CH2 < CH2=CHMe < CH2=CHBr), we can place CH2=CHOEt between CH2=CHMe and CH2=CHBr in terms of reactivity. This is because CH2=CHBr contains an electron-withdrawing bromine atom, which decreases the reactivity compared to CH2=CHOEt.
In summary, CH2=CHCO2Et (α,β-unsaturated ester) is less reactive than CH2=CHOEt (aldehyde) in electrophilic addition reactions, and the reactivity order is:
CH2=CH2 < CH2=CHMe < CH2=CHOEt < CH2=CHBr