| 主权项 |
1. A compound of the formula wherein Y is S or O, and A is selected from the group consisting of —CH2—, —CH2—CH2—, —CH(CH3)—, —CH(CH3)—CH2—, and R1 is an unsubstituted or substituted aryl- or heteroaryl-group, and R3 is H, a methyl group or an ethyl group, and wherein R2 is H, a phosphoramidite, H-phosphonate or phosphate triester, or wherein R2 is or wherein R2 is wherein R4 is H, a phosphoramidite, H-phosphonate or phosphate triester, and wherein R5 is H, OH, a halogen or XR6, wherein X is O or S and R6 is H, an alkyl-group, aryl-group, or OR6 is a phosphoramidite, phosphodiester, phosphotriester, H-phosphonate or an acetal or silicone moiety, and wherein B is selected from the group consisting of adenine, cytosine, guanine, thymine, uracil, 2,6-diaminopurine-9-yl, hypoxanthin-9-yl, 5-methylcytosinyl-1-yl, 5-amino-4-imidazolecarboxylic acid-1-yl or 5-amino-4-imidazolecarboxylic acid amide-3-yl, wherein when B is adenine, cytosine or guanine the primary amino group optionally has a protecting group or when B is thymine or uracil at the O4 position is optionally a protecting group, or wherein R2 is wherein R7 is a natural amino acid, a non-natural amino acid or an amino acid derivative having a urethan bond to formula Ib, or wherein formula IV represents the carboxy function of a natural amino acid, a non-natural amino acid or an amino acid derivative, having an ester bond to formula Ib. |
