Rapamycin hdroxyesters, process for their preparation and pharmaceutical compositions containing them

A compound of structure (I) wherein R 1 and R 2 are each, independently, hydrogen or - CO(CR 3 R 4 ) b (CR 5 R 6 ) d CR 7 R 8 R 9 ; R 3 and R 4 are each, independently, hydrogen, alkyl, alkenyl, alkynyl, trifluoromethyl, or -F; R 5 and R 6 are each, independently, hydrogen, alkyl, alkenyl, alkynyl, -(CR 3 R 4 ) f OR 10 , -CF 3 , -F, or -CO 2 R 11 , or R 5 and R 6 may be taken together to form X or a cycloalkyl ring that is optionally mono-, di-, or tri-substituted with - (CR 3 R 4 ) f OR 10 ; R 7 is hydrogen, alkyl, alkenyl, alkynyl, -(CR 3 R 4 ) f OR 10 , -CF 3 , -F, or -CO 2 R 11 ; R 8 and R 9 are each, independently, hydrogen, alkyl, alkenyl, alkynyl, -(CR 3 R 4 ) f OR 10 , -CF 3 , -F, or -CO 2 R 11 , or R 8 and R 9 may be taken together to form X or a cycloalkyl ring that is optionally mono-, di-, or tri-substituted with -(CR 3 R 4 ) f OR 10 ; R 10 is hydrogen, alkyl, alkenyl, alkynyl, tri-(alkyl)silyl, tri-(alkyl)silylethyl, triphenylmethyl, benzyl, alkoxymethyl, tri-(alkyl)silylethoxymethyl, chloroethyl, or tetrahydropyranyl; R 11 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 R 1 and R 2 are both not hydrogen and further provided that either R 1 or R 2 contains at least one -(CR 3 R 4 ) f OR 10 , X, or -(CR 3 R 4 ) f OR 10 substituted cycloalkyl group, or a pharmaceutically acceptable salt thereof which is useful as an immunosuppressive, antiinflammatory, antifungal, antiproliferative, and antitumor agent.