help (tosylation mechanism)

[lutesium]

Hi
I am UTFSE in for many weeks for the reaction mechanisms of sulphur compounds. There are many educative posts but because I know absolutely nothing about the issue I cant understand many aspects of these posts. For example I read many posts who deal with the tosylation of alcohols but I cant understand why that tosyl group is replaced with the H of -OH group - what benefits does it offer?
I need help because I dont know where to start show me the basics of tosylation, which groups can be tosylated, what can the tosyl group be replaced with etc. and I can pull the rest.

Thanx

[Nicodem]

The tosyl group does not have much to do with the chemistry of sulphur compounds. Its utility lies in the fact that tosylates are electrophylic and the tosyl is an excellent leaving group. An tosyl ester has similar properties as an alkylhalogenide. It is even a better leaving group than a iodide, hence it is called a psudohalogenide group.
So start your search with these basic keywords:
tosylation, electrophilicity, nucleophylic substitution, pseudohal(ogen)ides ...
also

http://www.public.asu.edu/~iangould/331/handouts/nucleophilicityetc.pdf