Thymidine 5-phosphate polymerization

Attempted use of DMSO instead of pyridine as the solvent for the dicyclohexylcarbodiimide-promoted polymerization of thymidine 5 -phosphate, A, resulted in cleavage to produce thymine in quantitative yield. Suggest an explanation. 

Narang and Michniewicz (87) reported successful application of Avicel-cellulose plates for the rapid and efficient fractionation of complex chemically polymerized thymidine 5 -phosphate reaction mixtures, in situ quantitative analysis of the oligonucleotides on TLC plate by reflectant spectrophotometry, in situ identiflcation of the common mononucleosides and mononucleotides by double-scanning technique and fractionation of oligonucleotides on thick-layer Avicel-cellulose plates on a preparative scale. 

The polymerization of thymidine 5 -phosphate can be effected by dicy-clohexylcarbodiimide in anhydrous pyridine fS79). Di-, tri-, tetra-, and pentanucleotides have been isolated, identified, and degraded by spleen and venom phosphodiesterases 186). 

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