title: Regioselective Benzylation of 2-Deoxy-2-Aminosugars Using Crown Ethers: Application to a Shortened Synthesis of Hyaluronic Acid Oligomers.
abstract: The combination of benzyl bromide, sodium hydroxide and 15-crown-5 in tetrahydrofuran is shown to be an efficient method for installing benzyl groups at both the 4- and 6-positions regioselectively directly from peracetylatedN-trichloroacetyl-protected glucosamine and galactosamine. Application of this benzylation strategy proved to significantly shorten the synthetic route to hyaluronic acid tetra- and hexamers.
authors.affiliation: Department of Chemistry, Simon Hall, Indiana University, Bloomington, IN 47405-7003, USA.
authors.forename: Chinmoy
authors.initials: C
authors.lastname: Mukherjee
authors.affiliation: Department of Chemistry, Hach Hall, Iowa State University, Ames, Iowa 50011-3111, USA.
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Simon Hall, Indiana University, Bloomington, IN 47405-7003, USA.
authors.forename: Nicola L B
authors.initials: NL
authors.lastname: Pohl
keywords: Benzylation; carbohydrates; phase transfer; protecting groups; trichloroacetyl