The discovery of disease-related glycoproteins and potential biomarker glycopeptide molecules is accelerating through glycomics analysis [1]. In addition to methods for efficiently preparing glycans derived from natural samples [2], techniques for introducing glycans onto proteins by chemoenzymatic methods have also matured [3]. However, available glycans are still limited. For this reason, the field of chemical synthesis, which is capable of supplying the necessary glycans, is fundamental and important to glycoscience. Furthermore, in the functional analysis of glycans, the effectiveness of using nonnatural glycan structures, in addition to natural ones, is being demonstrated [4]. Therefore, to gain a new perspective on glycoprotein function, it is necessary to develop synthetic methods that can be expanded to prepare nonnatural glycan structures [5] with arbitrary modifications synthesizing glycan structures (Fig. 34.1).