Nucleosides. 121. Improved and general synthesis of 2'-deoxy-C-nucleosides. Synthesis of 5-(2-deoxy-.beta.-D-erythro-pentofuranosyl)uracil, -1-methyluracil, -1,3-dimethyluracil, and -isocytosine
A Practical Synthesis ofN1-Methyl-2′-deoxy-ψ-uridine (ψ-Thymidine) and Its Incorporation into G-Rich Triple Helix Forming Oligonucleotides
摘要:
A convenient synthesis of N1-methyl-2'-deoxy-psi-uridine (psi-thymidine, psi T, 7a) has been accomplished in good yield. The structural conformation of 7a was derived by 2D NMR and 1D NOE experiments. The nucleoside 7a has been incorporated into G-rich tripler forming oligonucleotides (TFOs) by solid-support, phosphoramidite method. The tripler forming capabilities of the modified TFOs (S4, S5 and S6) containing psi T has been evaluated in antiparallel motif with a target duplex (duplex-31) 5'd(CTGAGACCGGGAAGGAGGAAGGGCCAGTGAC)3'-5d(GACTCTGGCCCTTCCTCCTTCCCGGTCACTG)3' (D1) at pH 7.6. The tripler formation of modified homopyrimidine-oligomers (S1, S2 and S3) has also been studied in parallel motif with a duplex-10 (A(10):T-10) at pH 7.0.