Synthesis and properties of 2-azidodeoxyadenosine and its incorporation into oligodeoxynucleotides

2-Azidodeoxyadenosine (7) was conveniently synthesized from deoxyguanosine (2) by use of a combined reagent of TMSN3-BuONO. The Structure Of the tautomer of the azido derivative was determined by H-1 NMR. Reaction of 7 with iPr(2)NP(OEt)(2) gave an intermediate 10 of the Staudinger reaction. Incorporation of 7 into a DNA 13mer resulted in a significant decrease of the T-m value of the DNA duplex upon hybridization with the complementary strand. The thermal stability was discussed based on the hydrogen bond energy and electrostatic repulsion. (C) 2001 Elsevier Science Ltd. All rights reserved.