Patent ID: 8487092

Claim:
A compound of formula (S): wherein: SEM is 2-(trimethylsilyl)ethoxymethyl; R 2 is CHR 2A , and R 2A is independently selected from H, R, CO 2 R, COR, CHO, CO 2 H, and halo; R 6 and R 9 are independently selected from H, R, OH, OR, SH, SR, NH 2 , NHR, NRR', NO 2 , Me 3 Sn and halo; R 7 is independently selected from H, R, OH, OR, SH, SR, NH 2 , NHR, NRR', NO 2 , Me 3 Sn and halo; or the adjacent groups R 6 and R 7 together form a group —O—(CH 2 ) p —O—, where p is 1 or 2; and R is independently selected from optionally substituted C 1-12 alkyl, C 3-7 heterocyclyl and C 5-20 aryl groups, wherein the optional substituents are selected from C 1-7 alkyl, C 3-7 heterocyclyl, C 5-20 aryl, halo, hydroxy, C 1-7 alkoxy, C 3-7 heterocyclyloxy, and C 5-20 aryloxy; R″ is a C 3-12 alkylene group, which chain may be interrupted by one or more heteroatoms selected from O, S and N(H); and/or aromatic rings; each X is independently selected from O, S, or N(H); and R 2 ′, R 6 ′, R 7 ′, R 9 ′, and X′ are independently selected from the same groups as R 2 , R 6 , R 7 , R 9 , and X respectively; and wherein C 3-7 heterocyclyl pertains to a monovalent moiety obtained by removing a hydrogen atom from a ring atom of a heterocyclic compound, which moiety has from 3 to 7 ring atoms, of which from 1 to 4 are ring heteroatoms, selected from N, O and S.