Formation of deaminated products in styrene oxide reactions with deoxycytidine

The reaction of racemic styrene oxide with deoxycytidine under aqueous conditions was studied. The four principal products isolated were a pair of diastereomeric N-4-(2-hydroxy-1-phenylethyl)deoxycytidines (similar to 20% of the products) and a pair of diastereomeric 3-(2-hydroxy-2-phenylethyl)deoxyuridines (similar to 80% of the products). Reactions with optically active styrene oxides allowed the configurations of the 3-(2-hydroxy-2-phenylethyl)deoxyuridines to be assigned, and these structures were confirmed by an independent synthesis from deoxyuridine. Also, it was possible to tentatively assign the configurations of the N-4-(2-hydroxy-1-phenylethyl)deoxycytidines that had undergone some racemization during the reaction (the ratio of the retained to inverted configuration of the products was similar to 1:7).