The Domenico Scarlatti sonatas are available in a 10-volume set in the Music Library, but are not on reserve.  The sonatas are numbered using L (Longo) numbers, after the editor of these volumes, rather than the K (Kirkpatrick) numbers with which you may be more familiar.  If you want to find the equivalent L # for a K# sonata, please consult the Grove Music Online article.  At the bottom of the page at the above link, you will find a chart that lists the K and L #s for each of Scarlatti's sonatas.