Rs. Coleman et Ea. Kesicki, SYNTHESIS AND POSTSYNTHETIC MODIFICATION OF OLIGODEOXYNUCLEOTIDES CONTAINING 4-THIO-2'-DEOXYURIDINE (D(S4)U), Journal of the American Chemical Society, 116(26), 1994, pp. 11636-11642
Protected phosphoramidite 2 was used to incorporate synthetically the
non-natural nucleoside 4-thio-2'-deoxyuridine (d(S4)U) at a specified
position within oligonucleotide 3. Following DNA synthesis, the thioca
rbonyl group of the 4-thio-2'-deoxyuridine of 3 was modified chemosele
ctively and quantitatively with thiol-specific reagents to afford olig
onucleotides 14, 15, and 16 by S-alkylation or mixed disulfide formati
on. This protocol represents a divergent postsynthetic modification me
thod for incorporating a wide range of functional groups at any base p
osition within a DNA strand, starting from a single oligonucleotide in
termediate.