Facile synthesis of a cis–syn thymine dimer building block and its incorporation into oligodeoxynucleotides

The synthesis of a building block containing the photobiologically relevant cis–syn thymine cyclobutane photoproduct and its incorporation into oligonucleotides by the phosphoramidite-based solid-phase synthesis is reported. Compared to previous syntheses, this route is extremely short and allows such modified oligonucleotides to be easily available for biological studies.