| abstract |
The present invention provides the following structural formula I Wherein (a) R 2 is selected from the group consisting of C 0 -C 8 alkyl and C 1-4 -heteroalkyl, (b) X is a single bond, O, S, S (O) 2 and (C) U is an aliphatic linker in which one carbon atom is optionally replaced with O, NH, or S, and each such aliphatic linker is selected from R30 Optionally substituted with 1 to 4 independently selected substituents, (d) Y is selected from the group consisting of C, NH, and a single bond; (e) E is C (R3) ( R4) A or A.), and stereoisomers, pharmaceutically acceptable salts, solvates and hydrates thereof. |