2001 carbohydrates

carbohydratesU 0500

30 - 209Stereoselective Synthesis of β-C-D-Glucopyranosides Using the Reac-tion of TMSCN and Grignard Reagents with Cyclic Five-MemberedSulfonium Salt Intermediates. — A highly stereoselective synthesisof β-C-glycosides (V) is presented, which involves formation of the arylthioadducts of glucal (I), followed by reaction with vinyl ethers (III) to form acyclic sulfonium salt intermediate, which is quenched with various C-nucleosideslike TmsCN or Grignard reagents (IV). The configuration of the glycoside isβ-D-gluco exclusively, while stereoselectivity of C–C-bond formation in the sidechain depends on the nature of nucleophile (IV) introduced. — (LIU, HUI;SMOLIAKOVA, IRINA P.; Tetrahedron 57 (2001) 15, 2973-2980; Dep. Chem.,Univ. N. Dak., Grand Forks, ND 58202, USA; EN)

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