Nucleoside and oligonucleotide analogues

A compound or a salt thereof selected from the group consisting of

• 2′-O,4′-C-ethyleneguanosine,
• 2′-O,4′-C-ethyleneadenosine,
• 3′,5′-di-O-benzyl-2′-O,4′-C-ethylene-6-N-benzoyladenosine,
• 3′,5′-di-O-benzyl-2′-O,4′-C-ethylene-2-N-isobutyrylguanosine,
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethylene-6-N-benzoyladenosine,
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethylene-2-N-isobutyrylguanosine,
• 2′-O,4′-C-ethylene-2-N-isobutyrylguanosine,
• 2′O,4′-C-ethylene-6-N-benzoyladenosine,
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethylene-6-N-benzoyladenosine-3′-O-(2-cyanoethyl N,N-diisopropyl)phosphoramidite,
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethylene-2-N-isobutyrylguanosine-3′-O-(2-cyanoethyl N,N-diisopropyl)phosphoramidite,
• 2′-O,4′-C-ethyleneuridine,
• 2′-O,4′-C-ethylene-5-methyluridine,
• 2′-O,4′-C-ethylenecytidine,
• 2′-O,4′-C-ethylene-5-methylcytidine,
• 3′,5′-di-O-benzyl-2′-O,4′-C-ethyleneuridine,
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethyleneuridine,
• 3′,5′-di-O-benzyl-2′-O,4′-C-ethylene-5-methyluridine,
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethylene-5-methyluridine,
• 3′,5′-di-O-benzyl-2′-O,4′-C-ethylene-4-N-benzoylcytidine,
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethylene-4-N-benzoylcytidine,
• 3′,5′-di-O-benzyl-2′-O,4′-C-ethylene-4-N-benzoyl-5-methylcytidine,
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethylene-4-N-benzoyl-5-methylcytidine,
• 2′-O,4′-C-ethylene-4-N-benzoylcytidine,
• 2′-O,4′-C-ethylene-4-N-benzoyl-5-methylcytidine,
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethylene-uridine-3′-O-(2-cyanoethyl N,N-diisopropyl)phosphoramidite,
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethylene-5-methyluridine-3′-O-(2-cyanoethyl N,N-diisopropyl)phosphoramidite,
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethylene-4-N-benzoylcytidine-3′-O-(2-cyanoethyl N,N-diisopropyl)phosphoramidite, and
• 5′-O-dimethoxytrityl-2′-O,4′-C-ethylene-4-N-benzoyl-5-methylcytidine-3′-O-(2-cyanoethyl N,N-diisopropyl)phosphoramidite.

An oligonucleotide analogue comprising two or more nucleoside units wherein at least one of said nucleoside units is a structure of the formula (2):

• wherein:
• A represents a methylene group;
• and
• B is selected from the group consisting of an unsubstituted purin-9-yl group, an unsubstituted 2-oxo-pyrimidin-1-yl group, a purin-9-yl group substituted with at least one substituent α and a 2-oxo-pyrimidin-1-yl group substituted with at least one substituent α, said substituent α being selected from the group consisting of an unprotected hydroxyl group, a protected hydroxyl group, an alkoxy group having from 1 to 4 carbon atoms, an unprotected mercapto group, a protected mercapto group, an alkylthio group having from 1 to 4 carbon atoms, an unprotected amino group, a protected amino group, an amino group substituted by an alkyl group having from 1 to 4 carbon atoms, an alkyl group having from 1 to 4 carbon atoms and a halogen atom;
• or a salt thereof.

A pharmaceutical composition comprising a pharmaceutically effective amount of a pharmacologically active compound together with a carrier therefor, wherein said pharmacologically active compound is an oligonucleotide analogue comprising two or more nucleoside units, wherein at least one of said nucleoside units is a structure of the formula (2):

• wherein:
• A represents a methylene group;
• and
• B is selected from the group consisting of an unsubstituted purin-9-yl group, an unsubstituted 2-oxo-pyrimidin-1-yl group, a purin-9-yl group substituted with at least one substituent α and a 2-oxo-pyrimidin-1-yl group substituted with at least one substituent α, said substituent α being selected from the group consisting of an unprotected hydroxyl group, a protected hydroxyl group, an alkoxy group having from 1 to 4 carbon atoms, an unprotected mercapto group, a protected mercapto group, an alkylthio group having from 1 to 4 carbon atoms, an unprotected amino group, a protected amino group, an amino group substituted by an alkyl group having from 1 to 4 carbon atoms, an alkyl group having from 1 to 4 carbon atoms and a halogen atom;
• or a pharmacologically acceptable salt thereof.