4154
Table 1
Synthesis of C-glucosides by radical reactions with 2-O-allylsilyl-tethered substratesa
Tamao oxidation (entry 5). Similar treatment of 7 at 110°C in toluene further improved the yield of 5 to
85% (entry 6).
As described, we have developed an efficient method for preparing both 1α- and 1β-C-glucosides
having a 3-hydroxypropyl group at the anomeric position via the radical cyclization with an allylsilyl
tether. We demonstrated that the stereoselectivity of the radical cyclization can be controlled by the
conformation of the pyranose ring, which was effectively manipulated by the choice of the hydroxyl
protecting groups. The conversion of 4 and 5 into the potential IP3 ligands 2 and 3 is now under
investigation.
Acknowledgements
This investigation was supported in part by a Grant from the Ministry of Education, Science, Sports,
and Culture of Japan.
References
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1
flip of their conformation leading to an unusual C4-form, in which the bulky substituents are in axial positions due to