Ester Hydrolysis Reaction Mechanism - Acid Catalyzed & Base Promoted Organic Chemistry
ฝัง
- เผยแพร่เมื่อ 25 ธ.ค. 2016
- This organic chemistry video tutorial provides the mechanism of the ester hydrolysis reaction catalyzed by an acid or promoted under basic conditions. Under acidic conditions, the ester will be converted into a carboxylic acid and an alcohol. Under alkaline conditions, it will change to a carboxylate ion and an alcohol. This video contains plenty of examples and practice problems.
Final Exams and Video Playlists: www.video-tutor.net/
Just in case anyone had the same confusion as I did I sort of figured out why OCH3 is a bad Leaving Group (LG) during acid-catalyzed hydrolysis, but only when compared to its base-promoted counterpart. In basic conditions, the carbonyl Oxygen is not protonated initially, because the OH- molecules in the solution act as nucleophiles and attack the partially positive Carbonyl/middle carbon. In acidic conditions, the first step is the protonation of the carbonyl oxygen. Therefore, the resulting [tetrahedral intermediates] for each reaction are totally different.
As for the tetrahedral intermediates::: In basic conditions, the former carbonyl carbon has a negative charge (3 lone pairs + one bond to the carbon) which can recreate the double bond with carbon and then the molecule can kick off the OCH3 group. VERSUS... in acidic conditions the former carbonyl carbon is now an O-H group (after being protonated) and has a neutral charge (two lone pairs + 2 bonds, like it prefers), so there isn't a reason (?) for the Oxygen to donate an electron pair to the central carbon, and therefore the OCH3 wouldn't get "kicked off" naturally without further steps.
Hope this helps
Well explained sir. Thanks for the mechanism! It helps me a lot.
very comprehensible! Thanks!
Could you do a video on the Mechanism for Hydrolysis of an Ester with a tertiary alkyl group? Thanks your videos are great!
Thank you so much! It’s so calming watching these. Idk something about it makes me relax.
....youre watching these for fun? lol
@@allywalton6074 no. For my organic chemistry and watching them while doing my homework made the anxiety subside a little because the way he teaches and explains things has a soothing effect.
great videos. really helpful for my jee preparations
Yes, certainly!
Thank you once again.
Thanks for mechanism sir👏👏
Thanks!
im passing organic chemistry because of you
How far this help you
😂
thank you so much!
what would determine the rate of reaction for base-catalyzed hydrolysis of an ester if you had 3 different esters?
Would the Naoh not just form sodium methanoate when hydrolysing the methyl methanoate?
Thank you
You're welcome
Also in base catalysed why is och3 made to leave despite bad leaving group also it isnt protonated so still bad leaving group ..pls give me an answer as quickly as possible ..thanks
Thank u sir you helped me for 3 years straight now I am getting AAs ... Sir during protonation the reason for oxgen in red getting protonated may due to its more basic nature i.e. immobile lonepairs. Thnks
Do esters that can by hydrolised only with acid exist?
I don’t know how to say thanks
You know 😜
Too Mt keh m keh dunga Teri jagah 😂
Hi loved the video but at the beginning when you circled the Oxygen with the methyl group and said this “group was gonna leave” but when we went through the mechanism and saw it was only the methyl that leaves that confused me a bit 😅
You're just great❤️
Thank u!!
top tier
Sir,why in acidic medium methoxide ion is bad leaving group?? Pls reply...&thanks
I believe its because the acid will react with the OCH3 molecule instead of catalysing the reaction, thus making it a better “leaving group” in a base catalysis reaction
Where did the double bond in 4:19 go? And why is the white oxygen positive all the sudden???
Can you number the steps please. I like when the mechanisms look neat.
Thanks
Does PET hydrolyse in 10% HCl ? Thanks.
Good day,
Please can you describe what happens when a mixture of trialkylmonochlorosilane and dialkyldichlorosilane are hydrolysed. What are the products formed?
Bless 🙏🤗 you
Why ch3o- is stable in basuc medium?
is this the same thing as de-esterification?
Thx
8:05 if methanol is more acidic thwn water shouldn't its conjugate base be weaker than that of water?
base hydrolysis 7:17
I had a doubt in this, not anymore
Thank you for the video as always, super helpful!
But I'm struggling to understand why the methoxide ion can't exist in acidic conditions? My thought process is that in acidic environments there is a surplus of H+ ions to stabilise the methoxide anion and so it should be more stable? Can someone help me here
Acids dissociate in water or aqueous solutions to form ions. These are responsible for the conduction of electricity. Acids don't dissociate hydrogen ions in absence of water. Therefore, we can say that acids produce ions only in aqueous solutions.
sir please make video of p block ,metallurgy,surface chemistry , solid state, solutions , polymers,biomolecules
Unfortunately, I won't be ready any time soon to teach those subjects yet.
The Organic Chemistry Tutor wil they be completed in coming 2-3 months ?
The only video I plan on making in that list in the next few months is polymers. I'm going to stay away from the other topics for now.
Is it can be happened in neutral condition?
It's too slow solvent should act as a base or acid and that's not something to consider
please use a better software, sometimes things aren't clear
@The Organic Chemistry Tutor can u please say why och3- cannot exist in a acidic medium?..the video was wonderful though!!! ..
Can you do a video on orbital mechanics?
I don't know that field too well to teach it at this point. I'm going to stay with the common subjects taught in high school and college for now.
The Organic Chemistry Tutor ok I didn't know, but you videos are amazing.
Thanks.
i have feelings for you
Esters do not hydrolysie in acidic solution as far as i know
Yes they do.
In strong conc acid in water solvant it can easily hydrolyzed
1:25 - does the bond between the hydrogen and chlorine break due to the greater attraction of the H2O for another hydrogen being stronger than the covalent bond between the hydrogen and chlorine atom, or am I misunderstanding the mechanism?
Bro HCl is strong acid..so when dissolved in H2O it readily gives H+ and CL- ions. That's what a strong acid means...and then H+ attacks lone pair of oxygen in H2O and water is now protonated, we get H3O+