[chysce]

Hi there

I've tried using LiOH 4eq, than 2eq and I essentially cleave both esters. Bear in mind that I also have a glycosidic linkage in my molecule so acidic deprotection is a no go.

I was thinking of maybe using LiI or NaI in pyridine, but that's for systems where you have some EWG in alpha position. Also what comes to my mind is Na₂CO₃

[Dan]

I was thinking of maybe using LiI or NaI in pyridine, but that's for systems where you have some EWG in alpha position.

There is precedent for this, e.g. http://charette.corg.umontreal.ca/resume/EROS-ABC/Lithium_Iodide.pdf

If you have an α-EWG you will get decarboxylation (Krapcho reaction), but without it you should get the carboxylic acid.

[chysce]

Thanks for pointing that out. I will try with NaI since we dont have LiI in my lab at the moment.
I'll report back with the results.

[chysce]

I was thinking of maybe using LiI or NaI in pyridine, but that's for systems where you have some EWG in alpha position.

There is precedent for this, e.g. http://charette.corg.umontreal.ca/resume/EROS-ABC/Lithium_Iodide.pdf

If you have an α-EWG you will get decarboxylation (Krapcho reaction), but without it you should get the carboxylic acid.

I haven't managed to find any recent literature about methyl ester cleavages with LiI. All I was able to find is this: http://onlinelibrary.wiley.com/doi/10.1002/0471264180.or024.02/abstract. I used one of the procedures... 4eq of LiI in pyridine, but all i got is starting compounds :/

[Dan]

What about here:

http://onlinelibrary.wiley.com/doi/10.1002/0471264180.or024.02/abstract

Are you heating your reaction?

You can switch from pyridine to lutidine, collidine or DMF to reach higher temperatures.

[chysce]

You gave me the same paper i linked you Yeah i was considering DMF but i chose not to do in it since it degrades at high temperatures.
And yeah, I was refluxing it overnight and nothing happened.

[Dan]

You gave me the same paper i linked you Yeah i was considering DMF but i chose not to do in it since it degrades at high temperatures.
And yeah, I was refluxing it overnight and nothing happened.

Sorry, wasn't concentrating.

I agree re: DMF, I'd try lutidine first