Heptadeoxy-6(I-VII)-halo, -azido, and hepta-6(I-VII)S-hepta(N-Boc-2-amino)ethyl-6(I-VII)-heptathiomaltoheptaose derivatives were prepared by acetolysis of the corresponding per-C-6-modified beta-cyclodextrin derivatives. The rapid and convenient structural characterisation of all of the modified oligosaccharides by ESIMS is described.