Pronunciation of the "u" in the word "pure"

Hi...second post...

I'm an ESL tutor and use the text "Pronunciation Pairs" (Baker and Goldstein) when working on pronunciation with my students. Can someone tell me what the pronunciation symbol and the sample word is for the "u" in the word "pure"... my student and I were comparing the pronunciations of the words "poor"--uw (boot), "pour"--ow (no) and "pure"??? At this point I drew a blank...have gone through all the vowel sounds in the text and can't see any with this sound...am aware that it is the same sound as in cure, lure etc...but that's as far as I got. I'm thinking the answer is something that is staring me in the face but any help would be greatly appreaciated.

Tia...

Catherine