Two oligosaccharide derivatives, β-d-Glcp-(1−6)-β-d-Glcp-(1−6)-β-d-Glcp-(1−6)-β-d-Glcp-(1−4)-α-d-ManpOMe (1) and β-d-Glcp-(1−6)-β-d-Glcp-(1−6)-β-d-Glcp-(1−6) -β-d-Glcp-(1−6)-β-d-Glcp-(1−6)-β-d-Glcp-(1−4)-α-d-ManpOMe (2), have been synthesized efficiently using a convergent glycosylation strategy of 2 + 3 and 2 + 5. 1,6-Anhydro-β-d-glucopyranose, which was prepared from cotton pyrolysis, was applied as a key synthon in the synthesis, significantly simplifying the preparation. The bioassay suggested that these two oligosaccharides can both stimulate the growth of maize cultured in liquid medium at a concentration of 3 ppm.