Patent ID: 7329759

Claim:
A compound of formula I: wherein R 1 is (CH 2 ) n —X—Y, where n is 0 to 4; X is O or S or NH, and Y is (C 1 -C 8 )alkyl optionally substituted with 1-2 OH or 1-2 halo; or —(C 1 -C 8 )alkyl-O—(C 1 -C 8 )alkyl R 3 is H or (C 1 -C 4 )alkyl; R 4 is SCH 2 CO 2 (C 1 -C 4 )alkyl, —S—(C 6 -C 10 )aryl optionally substituted with halo, OH or (C 1 -C 4 )alkyl, or H; R 5 is H, OH or absent; R 6 is (C 1 -C 4 )alkyl; R 7 is OH or —O(Si((C 1 -C 4 )alkyl) 3 ; or R 6 and R 7 together are ethylenedioxy; R 8 is (C 1 -C 4 )alkyl optionally comprising OH or halo; the bond represented by ----- is present or absent; or a pharmaceutically acceptable salt thereof.