Two derivatives of β-maltosyl-(1→4)-trehalose monodeoxygenated at C-2 or C-2′ have been synthesized in [2+2] block syntheses.N-Iodosuccinimide-mediated coupling of tetra-O-benzyl-glucose to tri-O-acetyl-D-glucal followed byO-acetylation furnished 3,4,6-tri-O-acetyl-2-deoxy-2-iodo-α-D-mannopyranosyl 2,3,4,6-tetra-O-benzyl-α-D-glucopyranoside (7), which was used as a starting material for both tetrasaccharides. For the preparation of the 2′-monodeoxygenated saccharide the deoxyiodo pyranose moiety of7was further elaborated by de-O-acetylation,O-benzylidenation,O-benzylation, and selective reductive opening of the benzylidene acetal to give glycosyl acceptor10. Glycosylation with hepta-O-acetylmaltosyl bromide and deprotection including removal of the iodo substituent afforded the 2′-deoxymaltosyl-(1→4)-trehalose14. On the other hand, the non-iodinated pyranose moiety of7was transformed to a glycosyl acceptor. The removal of the benzyl groups of7necessitated also the reduction of the iodo group at this early stage. The resulting 3,4,6-tri-O-acetyl-2-deoxy-α-D-arabino-hexopyranosyl α-D-glucopyranoside was subjected to a similar reaction sequence as above to finally result in the 2-deoxymaltosyl-(1→4)-trehalose22.