Caffinehog - 7-3-2005 at 18:24
I'm familiar with tosylates and mesylates, but has anyone made anything like them at home? And is there any method, other than acid catalysis,
to make the O part of an alcohol into a good leaving group?
Nicodem - 8-3-2005 at 03:00
Well, this was surely discussed a lot. But what exactly are you more interested in? How to put a leaving group instead of OH (any group?), how to make
tosylate esters, or how to make p-tolylsulphonic or methanesulphonic acid at home?
If you just want any leaving group then I suggest you the halides which are most easily put there (especially the Br). I'm sure you can find many
posts dealing with the preparation of alkylhalides from alcohols (like using H2SO4/NaBr on R-OH). Another alternative are the monoalkylsulphates
(R-O-SO3H) which form easily from the alcohol with conc. H2SO4.
Tosic acid can be made from OTC materials (H2SO4, toluene). Its esters are however not so straightforward. There is a nice method that uses Co(AcO)2
as a catalyst though. MeSO3H or even CF3SO3H are expensive and as far as I know can't be prepared easily, surely not at home.