Rapamycin oximes

A compound of the structure wherein R1 is R2 is hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, or Ar; R3 is hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, or -CO2R8; R4 is alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, Ar, aminoalkyl, thioalkyl, alkylthioalkyl, hydroxyalkyl, or -CO2R8; R5 is hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, At, or -CO2R8; R6 is hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, or Ar; R7 is alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, or Ar; R8 is hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, fluorenylmethyl, or Ar; Y is O or S; X is =N-O-(CH2)f-Z or =N-O-Ar; Z is hydrogen, alkenyl, alkynyl, alkoxy, cyano, fluoro, trifluoromethyl, -NR5R6, aryloxy, or Ar; Ar is aryl which may be optionally mono-, di-, or tri- substituted; a=0-4; b=0-1; c=0-4; d=0-6; e=0-6; and f=0-6; or a pharmaceutically acceptable salt thereof, with the proviso that when f is 0, Z is hydrogen and further provided that when R3 or R5 is -CO2R8, R8 is not hydrogen which is useful as an immunosuppressive, antiinflammatory, antifungal, antiproliferative, and antitumor agent. A compound of the structure wherein R1 is R2 is hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, or Ar; R3 is hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, or -CO2R8; R4 is alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, Ar, aminoalkyl, thioalkyl, alkylthioalkyl, hydroxyalkyl, or -CO2R8; R5 is hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, At, or -CO2R8; R6 is hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, or Ar; R7 is alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, or Ar; R8 is hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, arylalkyl, fluorenylmethyl, or Ar; Y is O or S; X is =N-O-(CH2)f-Z or =N-O-Ar; Z is hydrogen, alkenyl, alkynyl, alkoxy, cyano, fluoro, trifluoromethyl, -NR5R6, aryloxy, or Ar; Ar is aryl which may be optionally mono-, di-, or tri- substituted; a=0-4; b=0-1; c=0-4; d=0-6; e=0-6; and f=0-6; or a pharmaceutically acceptable salt thereof, with the proviso that when f is 0, Z is hydrogen and further provided that when R3 or R5 is -CO2R8, R8 is not hydrogen which is useful as an immunosuppressive, antiinflammatory, antifungal, antiproliferative, and antitumor agent.