K. Yoshimoto, Takako Wakamiya, Y. Nishikawa
Apr 25, 1982
Citations
0
Influential Citations
7
Citations
Journal
Chemical & Pharmaceutical Bulletin
Abstract
2, 3, 2', 3'-Tetra-O-benzyl-α, α-trehalose was synthesized conveniently in improved yield according to the known pathway but under modified reaction conditions : namely, α, α-trehalose was treated with α, α-dimethoxytoluene to give its 4, 6 : 4', 6'-di-O-benzylidene derivative, which was benzylated with benzyl chloride in dimethylsulfoxide in the presence of sodium hydride, and subsequently debenzylidenated by hydrolysis with 80% acetic acid. Selective acylation of the key intermediate by reaction with 1.4 molar equivalents of stearoyl chloride, followed by catalytic hydrogenolysis over palladium black, afforded 6-O-stearoyl-α, α-trehalose, mp 116-122°C, [α]18D+108.2°(c=1.0, chloroform), and 6, 6'-di-O-stearoyl-α, α-trehalose, mp 157-160°C, [α]18D+80.8°(c=1.0, chloroform), in an approximate molar ratio of 1 : 3.8. Similarly, 4, 6, 4', 6'-tetra-O-stearoyl-α, α-trehalose, mp 95-97°C and 108-110°C (double melting point), [α]17D+54.5°(c=1.0, chloroform), was also obtained by the use of 4 molar equivalents of acid chloride. Based on comparison of the carbon-13 nuclear magnetic resonance (13C NMR) spectral data and thin-layer and gas-liquid chromatographic behavior, the major components contained in the monoand diester preparations which had been produced in our previous work by transesterification of α, α-trehalose with methyl stearate and shown to possess interesting biological activities were identified as the 6- and 6, 6'-stearates, respectively.