Heterocyclic Substituted Hexahydropyrano[3,4-d][1,3]Thiazin-2-Amine Compounds

A compound having the absolute stereochemistry of Formula I

• wherein
• R1 is hydrogen or methyl, wherein said methyl is optionally substituted with one to three fluoro;
• R2 is a 5- to 6-membered heteroaryl, having one to three heteroatoms selected from N, O or S, wherein at least one of the heteroatoms is S or N and wherein said N is optionally substituted with R4;
• and wherein said heteroaryl moiety is independently substituted at each available carbon position with R3a, R3b, R3c or R3d;
• R3a, R3b, R3c and R3d are independently hydrogen, halogen, —OH, —CN, C1-6alkyl, —OC1-6alkyl;
• —(CR5aR5b)m—C3-6cycloalkyl or —(CR5aR5b)m—C3-6heterocycloalkyl;
• wherein said alkyl is optionally substituted with one to three fluoro and wherein said cycloalkyl and heterocycloalkyl moieties are optionally substituted with one to three fluoro, —CH3, —CH2F, —CHF2 or —CF3;
• R4 is hydrogen, C1-6alkyl, or —(CR5aR5b)m—C3-6cycloalkyl;
• wherein said alkyl and cycloalkyl are optionally substituted with one to three fluoro, —OCH3 or —OCF3;
• R5a and R5b are independently hydrogen, —CH3, —CH2F, —CHF2, —CF3 or —OCH3;
• and
• m is 0, 1 or 2;
• or a tautomer thereof or a pharmaceutically acceptable salt of said compound or tautomer.