Coupling is generally either not seen or very weak when it comes to hydroxyl protons (or indeed any heteroatom-bonded proton) on account of the rapid exchange rate, and thus short period of residency on the heteroatom, shorter than the time required for an NMR transition. This page gives some values to this:
"Under normal conditions for NMR spectra acquisition, no coupling is observed between the hydroxyl hydrogen and hydrogens on the carbon atom to which the hydroxyl group is attached. A typical alcohol undergoes intermolecular proton exchange at a rate of 105 protons per second. This means that the average time of residence of a proton on oxygen is 10-5 seconds. About 10-2 to 10-3 second is required for an NMR transition event to occur and be recorded. As far as the NMR spectrometer is concerned, the hydroxyl proton is unattached more frequently than it is attached to oxygen, and the spin interaction between the hydroxyl proton and any other proton in the molecule is effectively decoupled."
http://www.chemistry.ccsu.edu/glagovich/teaching/316/nmr/couplingoxygen.htmlBut I'm really struggling to find any published work to back these values up. I don't doubt them, they sound very reasonable, but I'd rather not reference a webpage in a paper! Can anyone think of anything published?