title: alpha-selective sialylations at -78 degrees C in nitrile solvents with a 1-adamantanyl thiosialoside.
abstract: Novel 1-adamantanylthio sialosides were synthesized and coupled to acceptors under NIS/TfOH promotion conditions. These donors showed higher reactivity than the phenylthio sialosides and could be activated by NIS/TfOH in nitrile solvents at -78 degrees C to afford improved alpha-sialylations. With the N-acetyl-5-N,4-O-oxazolidinone-protected 1-adamantanylthio sialyl donor high alpha-selectivities could be achieved in the sialylations of both primary and sterically hindered secondary acceptors, including the important galactose 3-OH acceptors.
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, USA. dcrich@chem.wayne.edu
authors.forename: David
authors.initials: D
authors.lastname: Crich
authors.forename: Wenju
authors.initials: W
authors.lastname: Li
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives*; D006027:Glycosides / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry; D012794:Sialic Acids / Q000737:chemistry*; D012997:Solvents; D013438:Sulfhydryl Compounds / Q000737:chemistry*