Regio- and stereo-controlled synthesis of β-Xyl(1–4)Rbo-5P1-Rbo, the partial structure of O-mannosyl glycan

•Partial structures of O-mannnosyl glycan, Xyl-Rbo-R (R = P, H, P-Rbo) were synthesized.•Structure of Xyl-Rbo-P-Rbo in O-mannosyl glycan was first identified by chemical reconstruction.•Xylosyl residue of the protected Xyl-Rbo existed as a conformational mixture of C1 and 1C form.•All the xylosyl residues in Xyl-Rbo-R (R = P, H, P-Rbo) predominantly formed C1 conformation.