A newly designed ligand with the bipyridine scaffold (an analog of Bolm's ligand), in combination with Sc(OTf)3, exhibits high stereocontrol in the ring opening of meso‐epoxides with various alcohols providing 1,2‐alkoxyalcohols.
An improved Williamson etherification of hindered alcohols promoted by 15-crown-5 and sodium hydride
作者:Helen C. Aspinall、Nicholas Greeves、Wai-Man Lee、Edward G. McIver、Peter M. Smith
DOI:10.1016/s0040-4039(97)00965-9
日期:1997.6
15-crown-5 greatly facilitates Williamson ether synthesis when sodium hydride base is used in THF solvent. This mild yet versatile procedure has been employed in the synthesis of new homochiral polyether ligands and bis-allylic ethers which are inaccessible by conventional methods. (C) 1997 Elsevier Science Ltd.