Disclosed are novel gamma secretase inhibitors of the formula. Also disclosed are methods of inhibiting gamma-secretase, methods of treating neurodegenerative diseases, and methods of treating Alzheimer's Disease. Also disclosed are processes for preparing alkenes in one reaction step using a mixture of an aldehyde (or ketone) and an alkyl substituted with two electron withdrawing groups, and reacting the mixture with: (a) a sulfonyl halide (e.g., a sulfonyl chloride) and a basic tertiary amine, or, (b) a sulfonyl anhydride and a basic amine, or (c) an aryl-C(O)-halide and a basic tertiary amine, or (d) an aryl-C(O)—O—C(O)-aryl and a basic tertiary amine, or (e) an heteroaryl-C(O)-halide and a basic tertiary amine, or (f) a heteroaryl-C(O)—O—C(O)-heteroaryl and a basic tertiary amine.