*Article* **A Concise Synthesis of a BODIPY-Labeled Tetrasaccharide Related to the Antitumor PI-88**

**Juan Ventura <sup>1</sup> , Clara Uriel <sup>1</sup> , Ana M. Gomez 1,\* , Edurne Avellanal-Zaballa <sup>2</sup> , Jorge Bañuelos 2,\* , Inmaculada García-Moreno <sup>3</sup> and Jose Cristobal Lopez 1,\***


**Abstract:** A convergent synthetic route to a tetrasaccharide related to PI-88, which allows the incorporation of a fluorescent BODIPY-label at the reducing-end, has been developed. The strategy, which features the use of 1,2-methyl orthoesters (MeOEs) as glycosyl donors, illustrates the usefulness of suitably-designed BODIPY dyes as glycosyl labels in synthetic strategies towards fluorescentlytagged oligosaccharides.

**Keywords:** PI-88; glycosylation; 1,2-methyl orthoesters; BODIPY; fluorescent labeling
