Hi
I didn't explain myself. It inserts four *, as it didn't find the
entity. I'm using emacs 24.5.3 and org-mode 8.34, which is the maint
branch. I've also tried with plain emacs without configuration.

Kaushal Modi:
>>
>> On Tue, May 10, 2016 at 3:28 PM drymer <drymer@autistici.org> wrote:
>>
>>> I evaluated the
>>> functions, and supposedly it should something like \ast when executing
>>> C-u *, but it doesn't happen.
>>>
>>
> I reread your initial email.. so look like you see nothing getting inserted
> when in do "C-u *"? That is odd.
> 
> Can you do the following and see if things work as intended? If they do,
> then there's something conflicting with your config:
> 
> 1. Launch emacs -Q
> 2. Paste the whole code block from
> http://emacs.stackexchange.com/a/16746/115 to the *scratch* buffer and
> evaluate it.
> 3. Do C-x b something.org
> 4. M-x org-mode
> 5. Hit "C-u *"
> 6. You should see an asterisk being displayed, which is actually a
> prettified version of "\ast{}" which is what actually got inserted.
> 
> Also, please report your emacs and org-mode versions. I am using the latest
> build of emacs-25 branch from git and the latest build of org-mode master
> branch git.
>