Reactivity of propylene oxides towards deoxycytidine and identification of reaction products.

Deoxycytidine was reacted with four epoxides of varying alkylating rates: propylene oxide, glycidol, epichlorohydrin and trichloropropylene oxide. Deoxycytidine was chosen to compare the reactivities of these epoxides as all sites of possible alkylation, the oxygen and both nitrogens, are involved in base pairing in DNA. Reaction products were separated on HPLC. Products of the least and most reactive epoxides, propylene oxide and trichloropropylene oxide, were characterized by UV, IR, 360 MHz NMR and MS analysis. For the epichlorohydrin and glycidol reactions and all analytical separations, products were characterized by their HPLC retention times and UV spectra. While differences in reactivity among the epoxides towards specific nitrogen and oxygen sites were found, total reactivity correlated with Taft sigma-values of the substituent groups.