Patent ID: 7671198

Claim:
A compound of formula (Ib): wherein: R 1 is selected from hydrogen, —OH, and —OP 1 , wherein P 1 is a hydroxy-protecting group; A is selected from —OC(O)—, —S(O) 2 —, and a covalent bond; W is selected from —N(R 3 )C(O)R 4 , —N(R 5 )S(O) 2 R 6 , and a moiety of formula (a): wherein Z is selected from NC(O)R 4 , NS(O) 2 R 6 , S(O) 2 , NH, and NP 2 ; R 3 , R 4 , R 5 , and R 6 are independently C 1-3 alkyl; P 2 is an amino-protecting group; and n is 0 or 1; or a salt thereof.