Synthesis of the tetrasaccharide residue of clarhamnoside, a novel glycosphingolipid isolated from the marine sponge Agelas clathrodes.
A tetrasaccharide, alpha-l-Rhap-(1-->3)-beta-d-GalpNAc-(1-->6)-alpha-d-Galp-(1-->2)-alpha-d-Galp, the carbohydrate moiety of clarhamnoside isolated from the marine sponge Agelas clathrodes, was synthesized as its propyl glycoside via a convergent approach. The key steps to the synthetic strategy were the stereoselective construction of the reducing-end disaccharide alpha-d-Galp-(1-->2)-d-Galp (5) and efficient coupling with the terminal disaccharide alpha-l-Rhap-(1-->3)-d-GalpNAc building block, in which the N-phthalimido-protected trifluoroacetimidate 13 was proved to be an effective donor.
Ding
Ning
N
Key Laboratory of Marine Drugs, The Ministry of Education of China, School of Pharmacy, Ocean University of China, Qingdao 266003, China.
Wang
Peng
P
Zhang
Zaihong
Z
Liu
Yunpeng
Y
Li
Yingxia
Y
D047230:Agelas / Q000737:chemistry*; D000818:Animals; D002236:Carbohydrate Conformation; D005690:Galactose / Q000737:chemistry; D005699:Galactosylceramides / Q000138:chemical synthesis* / Q000737:chemistry / Q000302:isolation & purification*; D012210:Rhamnose / Q000737:chemistry
D005699:Galactosylceramides; C483920:clarhamnoside; D012210:Rhamnose; D005690:Galactose