Synthesis of two trisaccharides related to the hepatoprotective phenylethanoids leonoside E and F isolated from Leonurus japonicus Houtt

• Synthesis of two trisaccharides from a single disaccharide minimising protecting group manipulations.
• Use of La(OTf)3 in conjunction with N-iodosuccinimide for the activation of thioglycosides.
• Use of p-methoxyphenyl glycoside that can be removed selectively from the per-O-acetylated oligosaccharides.

The chemical synthesis of two trisaccharides related to leonoside E and F is reported. The target oligosaccharides were prepared in the form of their p-methoxyphenyl glycosides using a common disaccharide acceptor. All reaction steps were high yielding (>80%) and the stereoselective glycosylations were achieved by activation of the thioglycoside donors using N-iodosuccinimide in the presence of La(OTf)3.

Figure optionsDownload as PowerPoint slide