Sciencemadness Discussion Board

Acetaldehyde from ethyl acetate confusion

RingoStarr - 9-6-2015 at 19:51

Nicodem made a great post in this thread claiming that acetaldehyde can be obtained from hydrolysis of MeCOOCHClMe (potentially made from ethyl acetate and TCCA).

Wouldn't doing an acid or base hydrolysis on MeCOOCHClMe make acetic acid and 1-chloroethanol?

If it does make acetaldehyde then what is the other product? Does it matter if it is an acid or base hydrolysis?

Thank you in advance.

Metacelsus - 10-6-2015 at 08:38

1-chloroethanol will form acetaldehyde hydrate by hydrolysis.

Nicodem - 10-6-2015 at 10:25

Quote: Originally posted by Cheddite Cheese  
1-chloroethanol will form acetaldehyde hydrate by hydrolysis.

Not really, simply because 1-chloroethanol undergoes an HCl elimination to give acetaldehyde way before any hydrolysis could occur.
Quote: Originally posted by RingoStarr  
Wouldn't doing an acid or base hydrolysis on MeCOOCHClMe make acetic acid and 1-chloroethanol?

No, the products are either acetic acid and acetaldehyde, or acetyl chloride and acetaldehyde, depending on the synthetic method.
Quote:
If it does make acetaldehyde then what is the other product? Does it matter if it is an acid or base hydrolysis?

I'am not aware of any base hydrolysis of alpha-haloalkyl carboxylates. I would expect other side reactions would prevail in basic media. The literature methods are mainly hydrolysis in diluted hydrochloric acid (giving the aldehyde and the carboxylic acid), or the retro-acylation in the presence of a few mol% of anhydrous ZnCl2 when the resulting acyl chloride and the aldehyde can be distilled from the reaction mixture.

RingoStarr - 10-6-2015 at 20:14

Thank you xo much for your replies. Nicodem, your knowledge of chemistry is an inspiration. Now you have given me more than a good hint of what is going on I'll read up on the chenistry you mentioned.