I have already explained this. It really is very easy,just read what i have already said.
1. Setup for standard vacuum distillation. Standard setup with RB flasks in normal distillation setup with vacuum hose attached to the vacuum receiver.
2. Add the KOH and heat up to say 120-150, really doesn't matter. 150DegC is good as you don't need to stir for very long.
3. If you want, add vacuum for a few minutes to drive any water out.
4. Release vacuum and continue to stir with heat, disconnect hose from vacuum source. Go to bed or whatever
So the point is the glassware is STILL set up for vacuum distillation. Removing the hose from the vacuum source is all you need to do. The safrole won't evaporate and no smell is released.
5. Next day, add vacuum and get it so that the iso is bubbling in the flask, but not boiling over.
This is the only tricky part, if your heat is too high and your vacuum too much, you can get an instant distillation which is NOT what you want. Thats why i do it at a temperature between the bp of safrole and iso under full vacuum. That is, I add full vacuum at said temperature and if the reaction is complete, I get no bubbling and conclude the reaction IS complete. However, if i get some bubbling, i keep stirring until it goes away.
Practice will soon learn you your best conditions.
If you are satisfied that the bp is that of trans iso, and higher than safrole you are done. As said, it is easy to get bubbling but not distilling, let stir until bubbles subside, increase heat etc.
Normally takes about 30 minutes until you see the bp is way higher than the starting safrole under the SAME vacuum.
6. Crank up heat some more and vacuum distill your iso. No safrole forerun if you do what I said. 90-95% yield
7. Wash your flask with water. No crap to get rid of.
8. So I repeat, setup glassware for distilling, DONT just heat in a beaker with KOH, my posts never said that.
I cant explain this much better, hope this helps
Abacus.