title: Regioselectivity in the formation of di- and tri-6-O-mesitylenesulfonates of α-cyclodextrin.
abstract: The quantitative analysis of the reaction products for α-cyclodextrin (α-CD) with mesitylenesulfonyl chloride (MessCl) showed that di- and tri-mesitylenesulfonylation of the primary hydroxy groups of α-CD is regioselective. The reaction of mono-6-O-mesitylenesulfonyl-α-CD with MessCl in pyridine gave less 6(A),6(C)-di-O-mesitylenesulfonyl-α-CD than 6(A),6(B)-di-O-mesitylenesulfonyl-α-CD. The reaction of 6(A),6(D)-di-O-mesitylenesulfonyl-α-CD with MessCl gave less 6(A),6(B),6(E)-tri-O-mesitylenesulfonyl-α-CD than 6(A),6(B),6(D)-tri-O-mesitylenesulfonyl-α-CD. These results indicate that the mesitylenesulfonyl group attached to glucopyranose-A (Glc-A) retards further mesitylenesulfonylation of the primary hydroxy group of Glc-C. The (1)H NMR spectra of these modified α-CDs showed that the signal for the primary hydroxy and anomeric protons of Glc-C are significantly shifted upfield by the mesitylenesulfonyl group of Glc-A.
authors.affiliation: Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan. Electronic address: yoshikiyo@life.shimane-u.ac.jp.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yoshikiyo
authors.affiliation: Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan.
authors.forename: Misaki
authors.initials: M
authors.lastname: Shinjo
authors.affiliation: Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Matsui
authors.affiliation: Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan.
authors.forename: Tatsuyuki
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D013237:Stereoisomerism; D013379:Substrate Specificity; D013451:Sulfonic Acids / Q000737:chemistry*; D047391:alpha-Cyclodextrins / Q000737:chemistry*
chemical_list: D013451:Sulfonic Acids; D047391:alpha-Cyclodextrins; C032613:alpha-cyclodextrin
keywords: Mesitylenesulfonylation; Regioisomers; Regioselectivity; α-Cyclodextrin