Suppose 1,5-pentanediol were exposed to something like hydroiodic acid. Would the alkoxonium end of the diol be exposed to a nucleophilic attack by the remaining hydroxide at the other end for a ring formation? Or would the newly-free iodide ion be more competitive for substitution? Thanks!
edit: It was pointed out to me "newly-free iodide" was quite confusing. I meant it as though HI dissociated, the Hydrogen ion attacked one end of the diol, and the iodide from the HI being "newly-free". Now that one end of the diol has a good leaving group (H2O), is it more susceptible to be attacked by the iodide, or by the other end (OH) of the diol.