| 摘要 |
<p>The present ilnvention is directed to compounds represented by the following structural Formula (I), (c) W is O or S; (d) X is an optionally substituted Cl-C5 alkylene linker wherein one carbon atom of the linker may optionally be replaced. with O, NH, S, and optionally two carbons together may form a double bond; (e) Y is selected from the group consisting of C, O, S, NH and a single bond; and (f) E is selected from the group consisting of C(R3) (R4)A, A, and a substituted or unsubstituted group selected from the group consisting of (CH2)n COOR19.</p> |
