Solid supports and phosphoramidite building blocks for oligonucleotide conjugates

A compound of Formula I:

• wherein:
• each A and A1is independently selected from —CH2— or —(CH2)2;
• each E and E1is independently selected from —CH2— or —(CH2)2—;
• G is —C(═O)—L, wherein:
• L is a linking moiety —[[(CH2)gX1(CH2)h]—X2—[(CH2)iX3(CH2)j]]k—J, wherein:
• each g, h, i, j, and k is, independently, an integer from 0to 6;
• each X1, X2, and X3is, independently, —O—, —CH2—, —NH—, —C(═O)NH—, —NHC(═O)—, or —NHC(═O)NH—;
• and
• J is a hydroxy group alkylated with optionally protected N-acetyl-D-galactosamine;
• one of R and R1is selected from hydrogen, acetyl (“Ac”), or a protecting group of trityl type selected from (4-methoxyphenyl)diphenylmethyl (“MMT”), bis-(4-methoxyphenyl)phenylmethyl (“DMT”), tris-(4-methoxyphenyl)methyl (“TMT”), 9-phenylxanthen-9-yl, or 9-(p-methoxyphenyl)xanthen-9-yl;
• and
• the other of R and Riis selected from hydrogen, acetyl, PA, or Ll, wherein:
• PA is a phosphoramidite moiety:
• L1is (C=O)CH2CH2C(═O)-W or (C=O)CH2CH2C(═O)NH-W, wherein
• W is —OH, —O−, or a solid phase material selected from a controlled pore glass, an aminopropyl controlled pore glass, magnetic controlled pore glass, polymers of styrene, copolymers of styrene and divinylbenzene, controlled pore glass grafted with polymers of styrene, controlled pore glass grafted with copolymers of styrene and divinylbenzene, copolymers of styrene and divinylbenzene grafted with polyethyleneglycol, flat glass surface, or soluble support media.