Patent ID: 6861514

Claim:
A synthetic method comprising the steps of: (a) providing compound of formula IA, IB, IC or ID: wherein: W 1a is W 1b —H, OH, NH 2 or SH, where W 1b is a linking group; R 1 is H or a hydroxyl protecting group; B is a nucleobase; each R 21 is H, OH, F, or a group of formula Z—R 22 —(R 23 ) v ; Z is O, S, NH, or N—R 22 —(R 23 ) v R 22 is C 1 -C 20 alkyl, C 2 -C 20 alkenyl, or C 2 -C 20 alkynyl; R 23 is hydrogen, amino, halogen, hydroxyl, thiol, keto, carboxyl, nitro, nitroso, nitrile, trifluoromethyl, trifluoromethoxy, O-alkyl, S-alkyl, NH-alkyl, N-dialkyl, O-aryl, S-aryl, NH-aryl, O-aralkyl, S-aralkyl, NH-aralkyl, amino, N-phthalimido, imidazole, azido, hydrazino, hydroxylamino, isocyanato, sulfoxide, sulfone, sulfide, disulfide, silyl, aryl, heterocycle, carbocycle, intercalator, reporter molecule, conjugate, polyamine, polyamide, polyalkylene glycol, polyether; v is from 0 to about 10; or R 21 has one of the formulas: wherein: y1 is 0 or 1; y2 is 0 to 10; y3 is 1 to 10; E is N(R 41 )(R 42 ) or N═C(R 41 )(R 42 ); each R 41 and each R 42 is independently H, C 1 -C 10 alkyl, a nitrogen protecting group, or R 41 and R 42 taken together form a nitrogen protecting group; or R 41 and R 42 taken together with the N or C atom to which they are attached form a ring structure that can include at least one heteroatom selected from N and O; q is from zero to about 50, provided that when said compound has formula ID, q is at least 1; M is an optionally protected internucleoside linkage; (b) reacting said compound of formula I with a compound of formula II: wherein: R 30 is an amino protecting group; X 3 is a group of formula XII: wherein m is 1 or 2; R 4 is a hydroxyl group, or a protected hydroxyl group; to form a compound of formula IVA, IVB, IVC, or IVD: wherein: W 4 has the formula: where W 1 is a linking group, O, NH, or S; and treating said compound of formula IVA, IVB, IVC or IVD with a deprotecting reagent to form a compound of formula VA, VB, VC or VD: wherein W 5 has the formula: (c) condensing said compound of Formula V with a compound of Formula VI: wherein: R 5 is H or an amino protecting group; R 6 is H or an amino protecting group; to form a compound of Formula VIIA, VIIB, VIIC, or VIID: wherein W 7 has the formula: