A compound of structure (I) wherein R1 and R2 are each, independently, hydrogen or -CO(CR3R4)b(CR5R6)dCR7R8R9 ; R3 and R4 are each, independently, hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, or -F; R5 and R6 are each, independently, hydrogen, alkyl, alkenyl, alkynyl, -(CR3R4)fOR10, -CF3, -F, or -CO2R11, or R5 and R6 may be taken together to form X or a cycloalkyl ring that is optionally mono-, di-, or tri-substituted with -(CR3R4)fOR10; R7 is hydrogen, alkyl, alkenyl, alkynyl, -(CR3R4)fOR10, -CF3, -F, or -CO2R11; R8 and R9 are each, independently, hydrogen, alkyl, alkenyl, alkynyl, -(CR3R4)fOR10, -CF3, -F, or -CO2R11, or R8 and R9 may be taken together to form X or a cycloalkyl ring that is optionally mono-, di-, or tri-substituted with -(CR3R4)fOR10; R10 is hydrogen, alkyl, alkenyl, alkynyl, tri-(alkyl)silyl, tri-(alkyl)silylethyl, triphenylmethyl, benzyl, alkoxymethyl, tri-(alkyl)silylethoxymethyl, chloroethyl, or tetrahydropyranyl; R11 is hydrogen, alkyl, alkenyl, alkynyl, or phenylalkyl; X is 5-(2,2-dialkyl)[1,3]dioxanyl, 5-(2,2-dicycloalkyl)[1,3]dioxanyl, 4-(2,2-dialkyl)[1,3]-dioxanyl, 4-(2,2-dicycloalkyl)[1,3]dioxanyl, 4-(2,2-dialkyl)[1,3]dioxalanyl, or 4-(2,2-dicycloalkyl)[1,3]dioxalanyl; b = 0-6; d = 0-6; and f = 0-6 with the proviso that R1 and R2 are both not hydrogen and further provided that either R1 or R2 contains at least one -(CR3R4)fOR10, X, or -(CR3R4)fOR10 substituted cycloalkyl group, or a pharmaceutically acceptable salt thereof which is useful as an immunosuppressive, antiinflammatory, antifungal, antiproliferative, and antitumor agent.