title: Regioselective double capping of cyclodextrin scaffolds.
abstract: Four different regioselective double capping reactions were applied either to α- or β-cyclodextrin (CD) scaffolds. The first, which relied on the use of a rigid, bulky dialkylating reagent containing two trityl-like subunits, gave access to an A,B,D,E-tetrafunctionalised β-CD regioisomer in large scale reactions. Two further capping reactions, involving the dianions PhP(2-) and S(2- , led to the synthesis of new C(1)-symmetrical β-cyclodextrins in which pairs of neighbouring glucose units are linked by very short spacers. The last double capping reaction described allowed the high-yield preparation of unprecedented α- and β-cyclodextrins containing two sulfate handles. Proximal capping turned out to be favoured for each of the above difunctional reagents. The structural characterisation of the capped species was achieved by thorough NMR investigations as well as by single-crystal X-ray diffraction studies.
authors.affiliation: Laboratoire de Chimie Inorganique et Catalyse, Institut de Chimie UMR 7177 CNRS, Université de Strasbourg, Strasbourg, France.
authors.forename: Rafael
authors.initials: R
authors.lastname: Gramage-Doria
authors.forename: David
authors.initials: D
authors.lastname: Rodriguez-Lucena
authors.forename: Dominique
authors.initials: D
authors.lastname: Armspach
authors.forename: Coraline
authors.initials: C
authors.lastname: Egloff
authors.forename: Matthieu
authors.initials: M
authors.lastname: Jouffroy
authors.forename: Dominique
authors.initials: D
authors.lastname: Matt
authors.forename: Loïc
authors.initials: L
authors.lastname: Toupet