Sugars acetylenic derivatives, synthesis

Tronchet, J.M.J., and Bonenfant, A.P., C-Glycosyl derivatives. Part 42. Synthesis of novel types of C-glycosyl-derivatives from acetylenic sugars or their partial synthetic equivalents. Preliminary communication, Helv. Chim. Acta, 64, 2322, 1981. 

The branched-chain acetylenic sugar derivative (380) reacted with aliphatic and aromatic aldehydes in the presence of a strong base to give the alkynols (381) and the enones (382), respectively. The synthesis of analogues of (381) and the conversion of the analogues into substituted pyrazole derivatives are referred to" " in Chapter 9. 

Asymmetric synthesis of acetylenic alcohols is possible by reduction of the corresponding ketones with lithium aluminium hydride complexed with sugar derivatives the optical yields are 4—1%. The trimethylether of the naturally occurring robustol (30), from the leaves of Grevillea robusta A. Cunn., has been synthesized in 55 % yield via cupric acetate oxidative cycliza-tion of the diacetylene (31). ... 

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