Xylose-DNA containing the four natural bases

Abstract

Oligonucleotides containing (2'-deoxy-beta-D-xylofuranosyl)guanine have been prepared. For this purpose 2-aminoadenosine (5) was synthesized and converted to 2'-deoxy-beta-D-xyloguanosine (1). The related 2'-deoxy-beta-D-xyloisoguanosine (3) and 2'-deoxy-beta-D-xyloxanthosine (4) were also synthesized. Compound 1 was converted to the phosphonate and phosphoramidite building blocks 10 and 11, respectively. The oligodeoxynucleotide (5'-3')d(xG-xT-xA-xG-xA-xA-xT-xT-xC-xT-xA-xC-T) (18) formed a duplex with the same T-m as the parent (5'-3')-(G-T-A-G-A-A-T-T-C-T-A-C) (19), but with an inverted CD spectrum.