The invention provides N-cyclic sulfonamido compounds of Formula I ##STR00001## wherein A, B, R.sub.1, R.sub.1a, R.sub.2, R.sub.2a, R.sub.3 and R.sub.3a are as described in the specification. Compounds of Formula I are useful in treating or preventing cognitive disorders, such as Alzheimer's disease. The invention also encompasses pharmaceutical compositions comprising compounds of Formula I, methods of preparing compounds of formula I, and methods of treating cognitive disorders, such as Alzheimer's disease.