Inhibitors of aspartyl protease

A compound of formula I:

• or a pharmaceutically acceptable salt thereof, wherein:
• E′ is —SO2—;
• A is selected from —R1—C1-C6 alkyl, which is optionally substituted with one or more groups independently selected from hydroxy, C1-C4 alkoxy, Ht, —O-Ht, —NR2—CO—N(R2)2, —SO2—R2 or —CO—N(R2)2;
• or —R1—C2-C6 alkenyl, which is optionally substituted with one or more groups independently selected from hydroxy, C1-C4 alkoxy, Ht, —O-Ht, —NR2—CO—N(R2)2 or —CO—N(R2)2;
• R1 is —O—C(O)—;
• each Ht is independently selected from C3-C7 cycloalkyl;
• C5-C7 cycloalkenyl;
• C6-C14 aryl;
• or a 5-7 membered saturated or unsaturated heterocycle, containing one or more heteroatoms selected from N, O, or S;
• wherein said aryl or said heterocycle is optionally fused to Q;
• and wherein any member of said Ht is optionally substituted with one or more substituents independently selected from oxo, —OR2, SR2, —R2, —N(R2)(R2), —R2—OH, —CN, —CO2, —C(O)—N(R2)2, —S(O)2—N(R2)2, —N(R2)—C(O)—R2, —N(R2)—C(O)O—R2, —C(O)—R2, —S(O)n—R2, —OCF3, —S(O)n-Q, methylenedioxy, —N(R2)—S(O)2(R2), halo, —CF3,—NO2, Q, —OQ, —OR7, —SR7, —R7, —N(R2)(R7) or —N(R7)2;
• each Q is independently selected from a 3-7 membered saturated, partially saturated or unsaturated carbocyclic ring system;
• or a 5-7 membered saturated, partially saturated or unsaturated heterocyclic ring containing one or more heteroatoms selected from O, N, or S;
• wherein Q is optionally substituted with one or more groups selected from oxo, —OR2, —R2, —SO2R2, —SO2—N(R2)2, —N(R2)2, —N(R2)—C(O)—R2, —R2—OH, —CN, —CO2R2, —C(O)—N(R2)2, halo, —CF3;
• each R2 is independently selected from H, or C1-C4 alkyl,;
• and wherein said alkyl, when not a substituent of Q, is optionally substituted with Q or —OR3;
• wherein when said R2 is an —OR3 substituted moiety, said R3 in —OR3 may not be —OR2 substituted;
• B is absent;
• each x is independently 0 or 1;
• each R3 is independently selected from H, Ht, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C6 cycloalkyl or C5-C6 cycloalkenyl;
• wherein any member of said R3, except H, is optionally substituted with one or more substituents selected from —OR2, —C(O)—NH—R2, —S(O)n—N(R2)(R2), —N(R2)2, —N(R2)—C(O)—O(R2), —N(R2)—C(O)—N(R2), —N(R2)—C(O)—(R2), Ht, —CN, —SR2, —CO2R2, or NR2—C(O)—R2;
• each n is independently 1 or 2;
• G is H;
• D is benzyl;
• D′ is selected from C1-C15 alkyl, C2-C15 alkenyl or C2-C15 alkynyl, each of which contains one or more substituents selected from oxo, —CF3, —OCF3, —NO2, azido, —SH, —N(R3)—N(R3)2, —O—N(R3)2, —(R3)N—O—(R3), —CN, —CO2R3, —C(O)—N(R3)2, —S(O)n—N(R3)2, —N(R3)—C(O)—R3, —N(R3)—C(O)—N(R3)2, —N(R3)—C(O)—S(R3), —(O)—R3, —N(R3)—S(O)n(R3), —N(R3)—S(O)n—N(R3)2, —S—NR3—C(O)R3, —(S)N(R3)2, —C(S)R3, —NR3—C(O)OR3,—O—C(O)OR3, —O—C(O)N(R3)2, —NR3—C(S)R3, ═N—OH, ═N—OR3, ═N—N(R3)2, ═NR3, ═NNR3C(O)N(R3)2, ═NNR3C(O)OR3, ═NNR3S(O)n—N(R3)2, —NR3—C(S)OR3, —NR3—C(S)N(R3)2, —NR3—C[═N(R3)]—N(R3)2, —N(R3)—C[═N—NO2]—N(R3)2, —N(R3)—C[═N—NO2]—OR3, —N(R3)—C[═N—CN]—OR3, —N(R3)—C[═N—CN]—(R3)2, —OC(O)R3, —OC(S)R3, —OC(O)N(R3)2, —C(O)N(R3)—N(R3)2, —O—C(O)N(R3)—N(R3)2, O—C(O)N(OR3)(R3), N(R3)—N(R3)C(O)R3, N(R3)—OC(O)R3, N(R3)—OC(O)R3, N(R3)—OC(O)R3, —OC(S)N(R3)2, —OC(S)N(R3)(R3), or PO3—R3;
• E is selected from Ht;
• O-Ht;
• Ht-Ht;
• Ht fused with Ht;
• —O—R3;
• —N(R2)(R3);
• C1-C6 alkyl optionally substituted with one or more groups selected from R4 or Ht;
• C2-C6 alkenyl optionally substituted with one or more groups selected from R4 or Ht;
• C3-C6 saturated carbocycle optionally substituted with one or more groups selected from R4 or Ht;
• or C5-C6 unsaturated carbocycle optionally substituted with one or more groups selected from R4 or Ht;
• each R4 is independently selected from —OR2, —OR3, —SR2, —SOR2, —SO2R2, —CO2R2, —C(O)—NHR2, —C(O)—N(R2)2, —C(O)—NR2(OR2), —S(O)2—NHR2, halo, —NR2—C(O)—R2, —N(R2)2 or —CN;
• and
• each R7 is hydrogen.