A method for manufacturing neuraminic acid derivatives is provided, also synthetic intermediates of the neuraminic acid derivatives and methods for their manufacture, and neuraminic acid derivatives having high purity.[Means for solution] A synthetic intermediate compound represented by the formula (7) is provided:[wherein R3represents alkyl R4and R5each represents H, alkyl, phenyl, or together represent tetramethylene, pentamethylene, oxo].提供一種製造神經胺酸衍生物之方法,亦提供此神經胺酸衍生物之合成中間物及其製法,及具高純度之神經胺酸衍生物。[解決方式]提供一種合成中間物式(7)代表之化合物:[其中R3代表烷基;R4及R5各代表H、烷基、苯基,或兩者一起代表四亞甲基、五亞甲基、酮基]。
