✍ Scribed by Bart Ruttens; Pavol Kováč
No coin nor oath required. For personal study only.
The title disaccharide, 2‐{2‐{2‐[(2‐ethoxy‐3,4‐dioxocyclobut‐1‐en‐1‐yl)amino]ethoxy}ethoxy}ethyl 2‐O‐(3,6‐dideoxy‐α‐L‐xylo‐hexopyranosyl)‐β‐d‐galactopyranoside cyclic 4,6‐(potassium phosphate) (2), was synthesized from the two isomeric linker‐equipped galactose acceptors 9 and 10, obtained by phosphorylation of 2‐[2‐(2‐azidoethoxy)ethoxy]ethyl 3‐O‐benzyl‐β‐d‐galactopyranoside (8), which were glycosylated with ethyl 2,4‐di‐O‐benzyl‐3,6‐dideoxy‐1‐thio‐β‐l‐xylo‐hexopyranoside (12; Scheme). Mainly the fully protected α‐(1 → 2)‐linked products 13**α** and 14**α** were formed. Catalytic hydrogenolysis/hydrogenation effected global deprotection, thereby removing the chirality at the P‐atom, and simultaneously converted the azido group in the linker to an amino group (→ 15). Final treatment with diethyl squarate (= 3,4‐diethoxycyclobut‐3‐ene‐1,2‐dione) gave target compound 2, amenable for conjugation to proteins.
📜 SIMILAR VOLUMES
Treatment of methyl Ot-D-perosaminide (1) with y-butyrolactone gave the 2'-deoxy analogue of methyl 4,6-dideoxy-4-(3-deoxy-L-glycero-tetronamido)-a-D-mannopyranoside (13), the methyl a-glycoside of the intracatenary monosaccharide repeating unit of the O-polysaccharide of Vibrio cholerae O:1. The an
Methyl 4-(3-deoxy-L-glycero-tetronamido)-4,6-dideoxy-2-O-methyl-alpha-D- mannopyranoside was acetylated, and the fully protected methyl glycoside was treated with dichloromethyl methyl ether-ZnCl2 (DCMME-ZnCl2) reagent to give 3-O-acetyl-4-(2,4-di-O-acetyl-3- deoxy-L-glycero-tetronamido)-4,6-dideoxy