What are tosylates used for?
Just to retire this question,
Substitution of an alcoholic group is especially difficult....
.....and thus owes to the strength of the
On the other hand, with
The reaction is not very convenient in that you need fairly dry solvents, and tosyl chloride has a sour, buttery smell that your lab neighbours WILL complain of bitterly (and of course both pyridines and tertiary amines smell pretty rank), but once you have connected it to your organic radical you have a leaving group that can be facilely substituted by nucleophiles....say here azides...
And even moderate nucleophiles can displace the tosyl group....i.e. iodides and bromides.....