Patent ID: 7271165

Claim:
A compound having the formula: or a pharmaceutically acceptable salt thereof; wherein A is H, OH, or O—(C 1-6 alkyl); W is O, S, or NR 1 , wherein R 1 is H, or C 1-6 alkyl; X is H or COR 2 , wherein R 2 is C 1-6 alkyl or O—(C 3-7 alkyl); Y is H, Hal, or OR Y3 , wherein R Y3 is H or C 1-6 alkyl; Z is H, Hal, or OR Z3 , wherein R Z3 is H or C 1-6 alkyl; and R 4 is wherein R 22 is H, C 1-6 alkyl, C 6-12 aryl, COR 24 , CO 2 R 24 , CONHR 24 , CSR 24 , COSR 24 , CSOR 24 , CSNHR 24 , SO 2 R 24 , or SO 2 NHR 24 , wherein R 24 is C 1-6 alkyl or C 6-12 aryl, and r is 1 or 2.