Triethylamine → 2-(1-adamantyl)ethyl 2,3,4-tri-O-acetyl-1-thio-beta-L-fucopyranoside

Beteiligte Stoffe

Reaktionsschritte

A solution of 2,3,4-tri-O-acetyl-1-thio-β-L-fucopyranose (2.14 g, 7 mmol) and 2-(1-adamantyl)ethyl iodide (2.03 g, 7 mmol) in dichloromethane (40 ml) containing triethylamine (0.71 g) is kept under nitrogen for 3 days. The reaction mixture is washed successively with N hydrochloric acid, aqueous sodium bicarbonate and water. The dried solution is concentrated to a residue which is taken up in ethanol to remove crystals (0.3 g, 2-(1-adamantyl)ethyl iodide). The mother liquor is put on a silica gel column and eluted with 1% methanol in chloroform. The desired fractions are pooled and evaporated to give 2-(1-adamantyl)ethyl 2,3,4-tri-O-acetyl-1-thio-β-L-fucopyranoside (1.8 g, 66%), [α]D +18° (c, 1.5, chloroform). Deblocking of this material with sodium methoxide in methanol affords the title compound, m.p. 130°-131°, [α]D +31° (c, 1.07, chloroform).

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