The reaction of some cyclic and open-chain disulphides with methyl trifluoromethanesulphonate

Abstract

The rates of reaction of methyl trifluoromethanesulphonate with a number of cyclic and open-chain disulphides have been studied at various temperatures. The main products of the reactions have been identified as the corresponding methylsulphonium salts. The difference in reactivity between the fivemembered and other disulphides arises from a combination of both enthalpy and entropy effects.

Orthogonal Glycosylation Reactions on Solid Phase and Synthesis of a Library Consisting of a Complete Set of Fucosyl Galactose Isomers

“…[24] The synthesis of a disaccharide library was carried out with 17-20, which contain orthogonal leaving groups, and a fucosyl donor in the form of the phenylthioglycoside 21 (Scheme 1). The phenylthio group was activated chemoselectively over glycosyl fluoride with dimethyl(methylthio)-sulfonium trifluoromethanesulfonate (DMTST) [25,26] to yield disaccharides in generally good yields (TLC analysis). Individual anomers in the disaccharide mixtures 22-25 were not isolated at this stage, to avoid the unnecessary loss of some anomers.…”

Synthesis of deoxy and acylamino derivatives of lactose and use of these for probing the active site of Neisseria meningitidis N-acetylglucosaminyltransferase

“…Phenyl b-lactoside (1) . Dimethyl(thiomethyl)sulfonium triflate (DMTST) was prepared essentially as previously described, 12 and was stored under dry nitrogen at À20°C. Recombinant N. meningitidis b-(1!3)-N-acetylglucosaminyltransferase (GlcNAc-T) was prepared as described, 1 the unit definition was based on p-nitrophenyl b-lactoside as the substrate.…”

Influence of Serine O‐Glycosylation or O‐Phoshorylation Close to the vJun Nuclear Localisation Sequence on Nuclear Import

“…Compound 11 could be obtained in 41 % yield starting from D-glucosamine by following known procedures. [22] Activation of the glycosyl donor 11 with DMTST [23] induced coupling to acceptor 12 in high yield (Scheme 4). Reductive cleavage of the trichloroethoxycarbonyl group followed by acetylation resulted in the fully protected Ser building block 14 in high yield.…”