The Synthesis of the 2- and 2'-Monodeoxygenated Analogues of β-Maltosyl-(1→4)-Trehalose
Title:
The Synthesis of the 2- and 2'-Monodeoxygenated Analogues of β-Maltosyl-(1→4)-Trehalose
Author:
Wessel, Hans Peter Minder, Rudolf
Appeared in:
Journal of carbohydrate chemistry
Paging:
Volume 17 (1998) nr. 4-5 pages 567-586
Year:
1998-05-01
Contents:
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 by O-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 of 7 was further elaborated by de-O-acetylation, O-benzylidenation, O-benzylation, and selective reductive opening of the benzylidene acetal to give glycosyl acceptor 10. Glycosylation with hepta-O-acetylmaltosyl bromide and deprotection including removal of the iodo substituent afforded the 2'-deoxymaltosyl-(1→4)-trehalose 14. On the other hand, the non-iodinated pyranose moiety of 7 was transformed to a glycosyl acceptor. The removal of the benzyl groups of 7 necessitated 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)-trehalose 22.
Journal description