Study on the Development ofNeuritogenic Drug: Preparation of the BuildingBlocks of Ganglioside OSG-1 Analogue

• Main Authors: Ching-Chin Hsieh, 謝清智
• Other Authors: Yow-Fu Tsai
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/00513553636564007939

碩士 === 中原大學 === 化學研究所 === 95 === The compound OSG-1, isolated from the sea cucumber Ophiocoma scolopendrina, is a ganglioside containing disaccharides. The synthesis of OSG-1 and its building blocks , such as N-acetylneuramic acid (Neu5Ac), glucose, phytosphingosine and α-hydroxyfatty acid will be discussed in this thesis. The building unit, Neu-3, was synthesized starting from sialic acid via a three-step procedure, involving esterification, per-O-acetylation, and thiophenol glycolsylation in 86% overall yield. The glucose building unit, Glc-6, was prepared using glucose as starting material through a six-step sequence, involving per-O-acetylation, 4-methoxyphenol glycolsylation, deacetylation, protection of primary alcohol, benzylation and deprotection primary alcohol, to give the product Glc-6 in a overall yield of 37%. The building unit of phytosphingosine, Lyx-7, was using lyxose as starting material through a seven-step sequence, involving O-isopropylidene reaction, protection of primary alcohol, Wittig reaction, azidization and functional group transformation to give the product Lyx-7 in a overall yield of 21%. The prepartion of α-hydroxyfatty acid was carved by a facile route in this thesis. The building unit of α-hydroxyfatty acid, Mal-6, is made from D-(+)-malic acid through cyclohexylidene protection reaction, thioethanol glycolsylation, Wittig reaction, hydrogenation and hydrolysis to give the product, Mal-6, in 34%.