A facile Er(OTf)3-catalyzed synthesis of 2,3-unsaturated O- and S-glycosides

Er(OTf3 is a useful catalyst for the Ferrier rearrangement furnishing high yields of O- and S-glycosides. The transforination has wide applicability, cleaner reaction profiles, mild reaction conditions, and high stereoselectivity and the catalyst, which is also commercially available, can be recovered and reused. (c) 2007 Elsevier Ltd. All rights reserved.