Conversion of pent-4-enyl glycosides into glycosyl bromides
作者:Peter Konradsson、Bert Fraser-Reid
DOI:10.1039/c39890001124
日期:——
The unique features of pent-4-enylglycosides for chemospecific (a) protection and (b) activation of the anomeric centre have been exploited for the preparation of glycosylbromides under such mild conditions that oxidizable and acid sensitive protecting groups are not affected, and in such excellent yields that the product can be used in situ for saccharide coupling.
Scope and Limitations of 2-Deoxy- and 2,6-Dideoxyglycosyl Bromides as Donors for the Synthesis of β-2-Deoxy- and β-2,6-Dideoxyglycosides
作者:Miho Kaneko、Seth B. Herzon
DOI:10.1021/ol501101f
日期:2014.5.16
It is shown that 2-deoxy- and 2,6-dideoxyglycosyl bromides can be prepared in high yield (72–94%) and engaged in glycosylation reactions with β:α selectivities ≥6:1. Yields of product are 44–90%. Fully armed 2-deoxyglycoside donors are viable, while 2,6-dideoxyglycosides require one electron-withdrawing substituent for high efficiency and β-selectivity. Equatorial C-3 ester protecting groups decrease