摘要 |
Compounds of formula (I) wherein R<1> is hydrogen, or a blocking group that is compatible with oligonucleotide synthesis; R<2> is hydrogen or methyl; R<3> is hydrogen or -P(R<4>)OR<5>; R<4> is chlorine, 4-nitroimidazole, imidazole, tetrazole, triazole or di(lower-alkyl)amino-; R<5> is methyl, 2-cyanoethyl or 2,2,2-trichloroethyl; n is from 0 to 2; X is oxygen, sulfur, or -NR<6>; R<6> is hydrogen or lower alkyl; Q is chosen from the group consisting of (a) and (b); R<7> is lower-alkyl; and R<8> is hydrogen, benzoyl, anisoyl, or lower-alkyl carbonyl and its pharmaceutically acceptable addition salts are nucleotide analogs. Modified oligonucleotides containing the nucleoside analogs of formula (I) are stable to nuclease degradation and are useful in inhibiting gene expression, in sequencing, and in mutagenesis. |