The present invention is directed to 2,6-morpholine derivatives of Formula (I): and pharmaceutically acceptable salts thereof, wherein Z1, Z2, V1, V2, V3, R6, R6A, and X are defined herein. The invention also relates to methods of using the 2,6-morpholine derivatives of the invention for the inhibition of HV protease, the inhibition of HV replication, the prophylaxis of infection by HIV, the treatment of infection by HIV, and the prophylaxis, treatment, and delay in the onset or progression of AIDS. The compounds and their salts can be employed as ingredients in pharmaceutical compositions, optionally in combination with other antivirals, immunomodulators, antibiotics or vaccines.