Improved synthesis of 5-hydroxymethyl-2'-deoxycytidine phosphoramidite using a 2'-deoxyuridine to 2'-deoxycytidine conversion without temporary protecting groups
(4), 1181-1184, 2011.Bioorg. Med. Chem. Lett. 21
5-Hydroxymethylcytosine has recently been characterized as the 'sixth base' in human DNA. To enable research on this DNA modification, we report an improved method for the synthesis of 5-hydroxymethyl-2'-deoxycytidine ((5-HOMe)dC) phosphoramidite for site-specific incorporation into oligonucleotides. To minimize manipulations we employed a temporary protecting group-free 2'-deoxyuridine to 2'-deoxycytidine conversion procedure that utilizes phase transfer catalysis. The desired (5-HOMe)dC phosphoramidite is obtained in six steps and 24% overall yield from 2'-deoxyuridine.