Different reaction routes found in acid-catalyzed glycosylation of endo- and exo-glycals: competition between Ferrier rearrangement and protonation
作者:Hui-Chang Lin、Wen-Ping Du、Chih-Chun Chang、Chun-Hung Lin
DOI:10.1016/j.tetlet.2005.05.061
日期:2005.7
products is often obtained resulting from Ferrier rearrangement and protonation. The former reaction exclusively takes place with the t-butyl carbonate or hydroxyl substituent at the C3 position of endo-glycals, while the latter mainly occurs in the glycosylation of exo-glycals with allyl benzyl ether or acetate. In addition to the substituenteffect, protecting groups are critical to determine the