Total synthesis of glycononaosyl ceramide with a sialyl dimeric Lex sequence |
| |
Authors: | Masami Iida Akira Endo Shuji Fujita Masaaki Numata Kazuo Suzuki Shigeki Nunomura Tomoya Ogawa |
| |
Institution: | (1) NISSIN FOOD PRODUCTS CO., LTD., Tokyo Research Institute, 1780, Kitano, Tokorozawa-shi, 359 Saitama, Japan;(2) The Institute of Physical and Chemical Research (RIKEN) Wako-shi, 351-01 Saitama, Japan;(3) Graduate School for Agricultural and Life Science, University of Tokyo, Yayoi, Bunkyo-ku, 113 Tokyo, Japan |
| |
Abstract: | The first total synthesis of glycononaosyl ceramide with a sialyl dimeric Lex sequence 1 is described. Regio- and stereo-selective glycosylations of sialyl donors 6,7,8 with the suitably protected Lex trisaccharide acceptors 9,10 were performed to give the expected tetrasaccharides 15 and 21, which were converted into the corresponding donors 20 and 22. Boron trifluoride etherate-promoted glycosylation of 20 with pentasaccharide acceptor 11 afforded regioselectively the expected nonasaccharide 23. After replacing benzyl groups of 23 by acetyl groups, the anomeric acetate was transformed into the -trichloroacetimidate 27. The crucial coupling between 27 and (2S, 3R, 4E-3-O-benzoyl-2-N-tetracosanoylsphingenine 3 was executed to afford completely protected -glycoside 28. Finally, selective cleavage of the methyl ester and N,O-deprotection of 28 gave the target ganglioside 1.Dedicated to Professor Sen-itiroh Hakomori on the occasion of his 65th birthday. |
| |
Keywords: | E-selectin P-selectin sialyl dimeric Lex glycolipid synthesis |
本文献已被 SpringerLink 等数据库收录! |
|