Patent ID: 8247372

Claim:
A Spiruchostatin analogue of formula (I) or (I′) including isosteres and pharmaceutically acceptable salts thereof; wherein R 1 , R 2 and R 4 , are the same or different and each is selected from —H, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, -L-O—C(O)—R′, -LC(O)—O—R′, -L-A, -L-NR″R″, -L-Het-C(O)-Het-R″ and -L-Het-R″, wherein L is a C 1 ,-C 6 alkylene group, A is phenyl or a 5- to 6-membered heteroaryl group, each R′ is the same or different and represents C 1 , -C 4 alkyl, each R″ is the same or different and represents H or C 1 ,-C 6 alkyl, each -Het- is the same or different and is a heteroatom spacer selected from —O—, -N(R′″)—and —S—and each R′″ is the same or different and represents H or C 1 ,-C 4 alkyl; R 3 is selected from —(C 1 -C 4 alkyl)-A″, —C 4 -C 6 alkenyl, -L-O—C(O)—R′, -L-C(O)—O—R″, -L-A, -L-NR″R″, -L-Het-C(O)-Het-R″ and -L-Het- R″, wherein A″is a C 6 -C 10 aryl group or a 5- to 10-membered heteroaryl group and A, L, R′, R″, R′″ and Het are as defined above; each R 6 is the same or different and represents hydrogen or C 1 ,-C 4 alkyl; and Pr 1 , Pr 2 and Pr 3 are each hydrogen.