Antioxidant inflammation modulators: oleanolic acid derivatives with amino and other modifications at C-17

A compound of the formula:

• wherein:
• X1 is hydrogen, ORb, NRbRc, or SRb, wherein Rb and Rc are each independently:
• hydrogen;
• alkyl(C≦8), aryl(C≦8), aralkyl(C≦8), acyl(C≦8), or a substituted version of any of these groups;
• or
• provided that Rb is absent when the atom to which it is bound is part of a double bond, further provided that when Rb is absent the atom to which it is bound is part of a double bond;
• R1′ is:
• hydrogen, cyano, hydroxy, halo, or amino;
• or
• alkyl(C≦8), alkenyl(C≦8), alkynyl(C≦8), aryl(C≦8), aralkyl(C≦8), heteroaryl(C≦8), heteroaralkyl(C≦8), acyl(C≦8), alkoxy(C≦8), aryloxy(C≦8), acyloxy(C≦8), alkylamino(C≦8), arylamino(C≦8), amido(C≦8), or a substituted version of any of these groups;
• R4 and R5 are each independently alkyl(C≦8) or substituted alkyl(C≦8);
• and
• R6 and R7 are each independently hydrogen or hydroxy;
• or a salt or a tautomer thereof.