C-H-Deprotonation Mediated by a Remote syn-Axial Acetoxy group – An unprecedented Double Bond Formation upon Cyanation of the Dimer from L-Fucal

Authors

Andreas H. Franz, University of the PacificFollow
Vyacheslav V. Samoshin, University of the PacificFollow
Chris Myers, Youngstown State University
Allen D. Hunter, Youngstown State University
Paul H. Gross, University of the PacificFollow

Document Type

Article

Publication Title

Carbohydrate Research

Department

Chemistry

ISSN

0008-6215

Volume

338

Issue

9

DOI

10.1016/S0008-6215(03)00048-X

First Page

851

Last Page

854

Publication Date

4-22-2003

Abstract

Replacement of the anomeric acetate by a cyanide group in the dimer of di-O-acetyl-l-fucal by the action of mild Lewis acid [Hg(CN)2HgBr2Me3SiCN], resulted not only in the desired transformation but also in the introduction of an additional double bond between C-2A and C-3A. Due to its configuration, the remote C-4A acetoxy group may facilitate the deprotonation by functioning as an internal base. 1H NMR spectroscopy and X-ray crystallography indicate that the conformations of both rings A and B and their relative orientation in the resulting C-linked disaccharidic glycosyl cyanide, 4-O-acetyl-2-C-(4-O-acetyl-2,3-dideoxy-α-l-threo-hex-2-enopyranosyl)-2,3-dideoxy-2-eno-α-l-fucopyranosyl cyanide, in solution are virtually identical to the crystal structure.

Recommended Citation

Franz, A. H., Samoshin, V. V., Myers, C., Hunter, A. D., & Gross, P. H. (2003). C-H-Deprotonation Mediated by a Remote syn-Axial Acetoxy group – An unprecedented Double Bond Formation upon Cyanation of the Dimer from L-Fucal. Carbohydrate Research, 338(9), 851–854. DOI: 10.1016/S0008-6215(03)00048-X
https://scholarlycommons.pacific.edu/cop-facarticles/130