Substituted oxazines as beta-secretase inhibitors

A compound of Formula I:

• or a pharmaceutically acceptable salt, stereoisomer, or tautomer thereof,
• wherein:
• R1 is H or C1-6 alkyl, wherein the C1-6 alkyl is optionally substituted with 1, 2, or 3 F substituents;
• R1′ is H or C1-6 alkyl, wherein the C1-6 alkyl is optionally substituted with 1, 2, or 3 F substituents;
• R2 is H, halogen, or OC1-6 alkyl, wherein the OC1-6 alkyl is optionally substituted with 1, 2, or 3 F substituents;
• R2′ is H, halogen, or OC1-6 alkyl, wherein the OC1-6 alkyl is optionally substituted with 1, 2, or 3 F substituents;
• R3 is C1-4 alkyl, optionally substituted with 1, 2, or 3 F substituents;
• R4 is halogen;
• R5 is H or F;
• (i) R6 is H or F;
• and
• R7 is pyridyl or pyrazinyl, wherein the pyridyl or pyrazinyl is optionally substituted with 1 or 2 substituents independently selected from the group consisting of halogen, CN, C1-6 alkyl, OC1-6 alkyl, OCH2C≡CH, and OCH2C≡CCH3, and further wherein the C1-6 alkyl and the OC1-6 alkyl are optionally and independently substituted with 1, 2, 3, 4, or 5 F substituents;
• or
• (ii) R6 is pyridyl or pyrazinyl, wherein the pyridyl or pyrazinyl is optionally substituted with 1 or 2 substituents independently selected from the group consisting of halogen, CN, C1-6 alkyl, OC1-6 alkyl, OCH2C≡CH, and OCH2C≡CCH3, and further wherein the C1-6 alkyl and the OC1-6 alkyl are optionally and independently substituted with 1, 2, 3, 4, or 5 F substituents;
• and
• R7 is H or F;
• and
• W is CH or N.