Patent ID: 7351696

Claim:
A compound of formula (I) wherein R 1 is OC(O)(CH 2 ) m XR 7 ; R 2 is hydrogen or a hydroxyl protecting group; R 3 is hydrogen, C 1-4 alkyl or C 3-6 alkenyl optionally substituted by 9 to 10 membered fused bicyclic heteroaryl; R 4 is hydrogen, C 1-4 alkyl, C 3-7 cycloalkyl, C 3-6 alkenyl or a 5 or 6 membered heterocyclic group, wherein the alkyl, cycloalkyl, alkenyl and heterocyclic groups are optionally substituted by up to three substituents independently selected from optionally substituted 5 or 6 membered heterocyclic group, optionally substituted 5 or 6 membered heteroaryl, OR 8 , S(O) n R 8 , NR 8 R 9 , CONR 8 R 9 , halogen and cyano; R 5 is hydroxy, C 3-6 alkenyloxy optionally substituted by 9 to 10 membered fused bicyclic heteroaryl, or O(CH 2 ) p O(CH 2 ) q R 10, R 6 is hydroxy, or R 5 and R 6 taken together with the intervening atoms form a cyclic group having the following structure: wherein Y is a bivalent radical selected from —CH 2 —, —CH(CN)—, —O—, —N(R 11 )— and —CH(SR 11 )—; R 7 is a heterocyclic group having the following structure: R 8 and R 9 are each independently selected from hydrogen and C 1-4 alkyl; R 10 is hydrogen or NR 8 R 9 ; R 11 is hydrogen or C 1-4 alkyl substituted by a group selected from optionally substituted phenyl, optionally substituted 5 or 6 membered heteroaryl and optionally substituted 9 to 10 membered fused bicyclic heteroaryl; R 12 is hydrogen, C(O)OR 15 , C(O)NHR 15 or C(O)CH 2 NO 2 ; R 13 is C 1-4 alkyl optionally substituted by hydroxy or C 1-4 alkoxy, C 3-7 cycloalkyl, or optionally substituted phenyl or benzyl; R 14 is halogen, C 1-4 alkyl, C 1-4 thioalkyl, C 1-4 alkoxy, NH 2 , NH(C 1-4 alkyl) or N(C 1-4 alkyl) 2 ; R 15 is hydrogen or C 1-4 alkyl optionally substituted by up to three groups independently selected from halogen, C 1-4 alkoxy, OC(O)C 1-4 alkyl and OC(O)OC 14 alkyl; R 16 is hydrogen, C 1-4 alkyl, C 3-7 cycloalkyl, optionally substituted phenyl or benzyl, acetyl or benzoyl; R 17 is hydrogen or R 14 , or R 17 and R 13 are linked to form the bivalent radical —O(CH 2 ) 2 — or —(CH 2 ) v —; X is —U(CH 2 ) s Z- or X is a group selected from: U and Z independently are a divalent radical selected from —N(R 16 )—, —O—, —S(O) t —, —N(R 16 )C(O)—, —C(O)N(R 16 )— and —N[C(O)R 16 ]—; W is CR 17 or a nitrogen atom; m is 0 or an integer from 1 to 5; n, r and t are each independently selected from 0, 1 and 2; p and q are each independently selected from 1 to 6; s is an integer from 2 to 8; and v is 2 or 3; or a pharmaceutically acceptable salt thereof.