| abstract |
In one aspect, the present invention provides a protected ligand precursor having structure XXI n n n n n n n n n n wherein R 8 is independently at each occurrence a protected hydroxy group, a protected C 1 -C 3 hydroxyalkyl group, or a C 1 -C 3 alkyl group, and b is 0-4; R 9 -R 11 are independently at each occurrence hydrogen, a protected C 1 -C 3 hydroxyalkyl group, or a C 1 -C 3 alkyl group, with the proviso that at least one of R 8 -R 11 is a protected hydroxy group or a protected C 1 -C 3 hydroxyalkyl group; and R 12 and R 13 are independently at each occurrence acid sensitive protecting groups. |