- DAST-mediated regioselective anomeric group migration in saccharides.
DAST-mediated regioselective anomeric group migration in saccharides.
The Journal of organic chemistry (2009-05-16)
Po-Chiao Lin, Avijit Kumar Adak, Shau-Hua Ueng, Li-De Huang, Kuo-Ting Huang, Ja-an Annie Ho, Chun-Cheng Lin
PMID19441783
ABSTRACT
When saccharides bearing a sulfur, selenium, or oxygen substituent at the anomeric center and an unprotected hydroxyl group either at C-4 or C-6 were subjected to fluorination with DAST in dichloromethane, a regioselective migration of the anomeric substituent to the C-4 or C-6 position was observed. Certain saccharides gave a mixture of migration and normal fluorination products whereas others yielded mainly or exclusively migration products (beta-glycosyl fluorides). The high thermal and chemical stability of migrated glycosyl fluorides were demonstrated to be an important precursor for many significant carbohydrate analogies. It is therefore suggested that these migrations may have useful applications in organic synthesis.
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