TY  - BOOK
AU  - Gervay,J.
AU  - Nguyen,T.N.
AU  - Hadd,M.J.
TI  - Mechanistic studies on the stereoselective formation of glycosyl iodides: first characterization of ¢l-D-glycosyl iodides
KW  - GLYCOSYL IODIDES
KW  - BETA-D-GLYCOSYL IODIDES
KW  - NMR CHARACTERIZATION
N2  - Treatment of glycosyl acetates with one equivalent of iodotrimethylsilane at low temperature results in the quantitative formation of glycosyl iodides. Carbohydrates that possess a participating group at the C-2 position initially form /3-o-glycosyl iodides, which quickly equilibrate to the o~-iodo anomers. The /3 anomer of peracetylated glucose reacts faster than the ce anomer, presumably because the C-2 acetate can assist in displacing the silylated anomeric acetate. In contrast, the o~ anomer reacts faster than the /3 anomer in substrates lacking a participating group at C-2. For example, activation of 1-O-acetyl-2,3,4,6-tetra-Obenzyl-o~-D-glucopyranose leads to formation of the /3 iodide, while the corresponding /3 acetate produces the ce iodide. Although the /3 iodides quickly equilibrate to the o~ anomers, they can be prepared in sizable quantities at low temperatures where equilibration is slow. This report describes the first stereoselective formation and characterization of /3-D-glycosyl iodides
UR  - https://drive.google.com/file/d/1l0Z2Pnyh3PspuRw1zOg99as0ng-c47Ua/view?usp=drivesdk
ER  -