Hopefully someone more knowledgeable will respond. But short of that, you might look at this article: Moving from Aperture to Lightroom – Lightroom Solutions – John Beardsworth, starting with the section "The Old Method", which describes a manual method of moving your photos from Aperture to LR. Since Aperture and iPhoto shared a similar underlying library structure (according to what I read), this method might help you with manually moving from iPhoto to LR.
Thanks johnrellis. I had actually read Beardsworth's excellent article on converting from Aperture to Lightroom, and many more beside while planning this transition to get me ready to move from OS X Mavericks to Yosemite. I worked on a copy of my iPhoto library to try out the move to Lightroom, so nothing actually lost yet! In fact the conversion went really well, except that all the cataloging information in the "Title" field has disappeared. This was important identifying information in the form "lastname,firstname*yyyymmdd" so I can't transition without it.
What I'd like to know is (1) is this a bug in the converter that the "Title" field doesn't convert, and if so, has anyone developed a workaround e.g. an applescript to copy the title into the comments field (which did convert perfectly)?
(2) does the use of the " , " character or the " * " character mess with the converter, and if so has anyone developed a workaround e.g. an applescript to replace the offensive character with a tolerated one?
I don't know the answer to your questions. But I have one high-level suggestion: Try the "old method" (a manual method) Beardsworth describes on just a few photos, to see if Title gets properly imported. Lots of people have reported problems with the converter plugin, and I doubt that Adobe will respond any time soon (if ever) to making improvements on it.