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 A4-(2-hydroxy-lphenylethyDdeoxycytidines (-20% of the products) and a pair ofdiastereomeric 3-(2-hydroxy2-phenylethyDdeoxyuridines (-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 N4-(2-hydroxy-l-phenylethyl)deoxycytidines that had undergone some racemization during the reaction (the ratio of the retained to inverted configuration of the products was ~1:7).