Aspartyl protease inhibitors

Disclosed are certain substituted spiro iminopyrimidinones and other compounds of the formula I or a stereoisomer, tautomer, or pharmaceutically acceptable salt or solvate thereof, wherein U, W, A, R, R1, R2, R6a and R7, are as defined in the specification; and pharmaceutical compositions comprising the compounds of formula I. Also disclosed are methods of using such compounds and compositions to inhibit aspartyl protease, and to treat a variety of disease and indications including (but not limited) to cardiovascular disease and cognitive and neurodegenerative disease. The compounds of the present invention are disclosed for use alone or in combination with one or more additional active ingredients such as cholinesterase inhibitors and a muscarinic m1 agonist and/or m2 antagonists.