Stereoselective syntheses of C-(D-glucopyranosyl)alkenes.
alpha-D-Glucopyranose pentaacetate (1) was found to undergo stereoselective conversion in good yield into 3-(tetra-O-acetyl-alpha-D-glucopyranosyl)-1-propene (4) by treatment with allyltrimethylsilane and boron trifluoride etherate in acetonitrile. Similar treatment of methyl tetra-O-acetyl-alpha-D-glucopyranoside or tetra-O-acetyl-alpha-D-glucopyranosyl bromide also gave 4 in preference to its beta anomer, but net yields were lower. Similar reaction of 1 with (E)-penta-2,4-dienyltrimethylsilane afforded the readily polymerizable 5-(tetra-O-acetyl-alpha-D-glucopyranosyl)-(E)-1,3-pentadiene, accompanied by a minor proportion of its beta anomer.
Horton
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D
Department of Chemistry, Ohio State University, Columbus 43210.
Miyake
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T
D000475:Alkenes / Q000138:chemical synthesis*; D002236:Carbohydrate Conformation; D005947:Glucose / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009904:Optical Rotation; D013237:Stereoisomerism
D000475:Alkenes; D007202:Indicators and Reagents; D005947:Glucose