Patent ID: 6900301

Claim:
An oligonucleotide analogue in which at least some of the subunits of the analogue have the structure: wherein B x is a variable base moiety; Q is O, CH 2 , CHF or CF 2 ; X is H; OH; C 1 to C 10 lower alkyl, substituted lower alkyl, alkaryl or aralkyl; F; Cl; Br; CN; CF 3 ; OCF 3 ; OCN; O—, S—, or N-alkyl; O—, S—, or N-alkenyl; SOCH 3 ; SO 2 CH 3 ; ONO 2 ; NO 2 ; N 3 ; NH 2 ; heterocycloalkyl; heterocycloalkaryl; aminoalkylamino; polyalkylamino; substituted silyl; or an RNA cleaving group, wherein at least one X is OH; L 1 and L 4 are, independently, CH 2 , C═O, C═S, C—NH 2 , C—NHR 3 , C—OH, C—SH, C—O—R, or C—S—R 1 ; and L 2 and L 3 are, independently, CR 1 R 2 , C═CR 1 R 2 , C═NR 3 , P(O)R 4 , P(S)R 4 , C═O, C═S, O, S, SO, SO 2 , NR 3 or SiR 5 R 6 ; or, together, form part of an alkene, alkyne, aromatic ring, carbocycle or heterocycle, or L 1 , L 2 , L 3 and L 4 , together, comprise a —CH═N—NH—CH 2 — or —CH 2 —O—N═CH— moiety; R 1 and R 2 are, independently, H; OH; SH; NH 2 ; C 1 to C 10 alkyl, substituted alkyl, alkenyl, alkaryl or aralkyl; alkoxy; thioalkoxy; alkylamino; aralkylamino; substituted alkylamino; heterocycloalkyl; heterocycloalkylamino; aminoalkylamino; polyalkylamino; halo; formyl; keto; benzoxy; carboxamido; thiocarboxamido; ester; thioester; carboxamidine; carbamyl; ureido; guanidino; or an RNA cleaving group; R 3 is H, OH, NH 2 , lower alkyl, substituted lower alkyl, alkoxy, lower alkenyl, aralkyl, alkylamino, aralkylamino, substituted alkylamino, heterocyclocalkyl, heterocycloalkylamino, aminoalkylamino, polyalkylamino, or an RNA cleaving group; R 4 is OH, SH, NH 2 , O-alkyl, S-alkyl, NH-alkyl, O-alkylheterocycle, S-alkylheterocycle, N-alkylheterocycle or a nitrogen-containing heterocycle; and R 5 and R 6 are, independently, C 1 to C 6 alkyl or alkoxy; provided that if L 1 is C═O or C═S then L 2 is not NR 3 or if L 4 is C═O or C═S then L 3 is not NR 3 ; and that if one of L 2 or L 3 is C═O or C═S then the other of L 2 or L 3 is not NR 3 ; and if L 2 is P(O)R 4 and R 4 is OH and X is OH and B x is uracil or adenine, then L 3 is not O; that if L 1 , L 2 and L 4 are CH 2 and X is H or OH and Q is O then L 3 is not S, SO or SO 2 .