[Lynda92]

Can t-butyl esters be cleaved using acetic acid? How stable are they in these acids?

[TheUnassuming]

It probably depends on the exact t-butyl ester.
Personally I've seen acetic acid cleave t-butyl esters when I wasn't careful enough stripping solvent after running a column with 1% AcOH.
Are you trying to cleave a t-butyl ester or trying to keep it on? 

[Lynda92]

It probably depends on the exact t-butyl ester.
Personally I've seen acetic acid cleave t-butyl esters when I wasn't careful enough stripping solvent after running a column with 1% AcOH.
Are you trying to cleave a t-butyl ester or trying to keep it on?

I'm having the exact same problem as you have stated. I'm trying to keep the t-butyl on but I did  a reaction where I had to column with DCM/MeOH/AcOH with the AcOH at 1% percent. I didn't get all the AcOH off my collected fractions until the next day.The nmr shows a small peak next to my t-butyl peak could this explain this posibility?This small peak wasn't in my starting material

[PhDoc]

Is the t-butyl ester a necessary functionality, or is it a protective group? Do you really need the HOAc for the separation? Do you have a picture of your compound?

[TheUnassuming]

The solution for me was simply never to let it get concentrated with AcOH.  So when you collect your fractions, dilute the solution with a good amount of toluene(~1ml toluene:2ml fraction volume).  When you rotovap it down, the toluene will azeotrope the AcOH so it will never get concentrated enough to cause decomposition. 

[PhDoc]

Lynda, I know toluene is a suggested solvent, however the azeotrope is HOAc:PhMe of 38:62, meaning that your solution will become concentrated with HOAc at some point. Also, the boiling point of PhMe is 110C, hence many students heat the solution at ~45C using a rotary evaporator. Heptane boils at 90C, and gives an azeotrope HOAc:Hept of 33:67.

If you're convinced the heat is not the issue, then you may want to try using dioxane, azeotrope HOAc:Diox of 83:17. I had an acetic acid issue once, and when I turned to dioxane, never again.

I hope this helps.