N-Acetylneuraminic acid aldolase (NeuAcA) (EC 4.1.3.3) is a pyruvate-dependent class I aldolase that catalyzes the reversible aldol cleavage of N-acetylneuraminic acid to form N-acetyl-D-mannosamine and pyruvate. The synthetic activity of this enzyme has been applied to the preparation of many sialic acid analogues. In this report, we demonstrate the ability of NeuAcA from Clostridium perfringens to use 2-oxoethyl substituted nucleobases as unusual acceptor substrates to perform aldol additions. In this way, novel acyclic nucleoside analogues bearing a further derivatizable 4-hydroxy-2-oxo butyrate skeleton were prepared in good yields.

Ñ -Acetylneuraminic酸醛缩酶（NeuAcA）（EC 4.1.3.3）是一种丙酮酸依赖性I类醛缩酶催化的醛醇可逆裂解Ñ -acetylneuraminic酸以形成Ñ乙酰基d甘露糖胺和丙酮酸盐。该酶的合成活性已被用于制备许多唾液酸类似物。在此报告中，我们证明了产气荚膜梭状芽胞杆菌的NeuAcA使用2-氧乙基取代的核碱基作为不寻常的受体底物来进行羟醛加成的能力。以这种方式，以高收率制备了带有进一步可衍生的4-羟基-2-氧代丁酸酯骨架的新型无环核苷类似物。