“Standardized intermediates” for oligosaccharide synthesis. A convenient preparation of partially benzylated derivatives of allyl 2-acetamido-2-deoxy-α-d-galactopyranoside having chain extension at position 4

✍ Scribed by Mina A. Nashed; Ramadan I. El-Sokkary; Latif Rateb

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 426 KB
• Volume: 131
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(84)85402-6

✦ Synopsis

Ally1 2-acetamido-2-deoxy-cy-D-galactopyranoside (5) was prepared from the corresponding &co compound, ally1 2-acetamido-2-deoxy-a-D-glucopyranoside (l), by successive selective benzoylation at O-3 and O-6, p-bromobenzenesulfonylation, displacement with cesium benzoate, and 0-debenzoylation. Ally1 2acetamido-3,6-di-O-benzyl-Zdeoxy-a-D-galactopyranoside (10) was prepared from 5 via the 4,6-benzylidene acetal 6, which was successive benzylated and subjected to mild acid hydrolysis to furnish the diol 8. Selective benzylation of O-6 was then accomplished by the action of a-bromotoluene on the 4,6-O-dibutylstannylene derivative 9.