Glycal

About: Glycal is a research topic. Over the lifetime, 897 publications have been published within this topic receiving 17422 citations.

Lewis acid catalyzed cyclization of glycals/2-deoxy-D-ribose with arylamines: additional findings on product structure and reaction diastereoselectivity.

Abstract: The cyclization reactions of arylamines with 2-deoxy-d-ribose or glycals were reinvestigated in the current report. In the montmorillonite KSF- or InCl3-initiated reactions of 2-deoxy-d-ribose with arylamines, a pair of diastereomeric tetrahydro-2H-pyran-fused tetrahydroquinolines was obtained in a nearly 1:1 ratio where the structure of one diastereomer was incorrectly assigned in the literature. Meanwhile, the diastereoselectivity in InBr3-catalyzed cyclization of glycals with arylamines was also incorrectly reported previously. It was found that high diastereomeric selectivity was achieved only when a C5-substituted glycal was used; otherwise, a pair of diastereomers was obtained in moderate yield with 1:1 diastereomeric ratio. Furthermore, tetrahydrofuran-fused tetrahydroquinolines 5b and 5b′ were also prepared successfully by using TBDPS-protected ribose as the glycal precursor and montmorillonite KSF as the activator.

Synthesis of 2′,3′-Dideoxy-D-erythro-hexofuranosyl Nucleosides and 3′-Azido-2′, 3′-dideoxy-D-arabino-hexofuranosyl Nucleosides From Tri-O-acetyl-D-glucal via an α,β-Unsaturated Hexose Alde

Abstract: α,β-Unsaturated aldehyde prepared from tri-O-acetyl-D-glucal was acetalated and benzoylated to give α,β-unsaturated acetal . Hydrogenation of the double bond followed by methanolysis resulted in methyl 2,3-dideoxyfuranosyl glycoside which was used for nucleoside coupling with silylated N 6 -isobutyrylcytosine and silylated thymine. Protected 3-azido-2,3-dideoxy-arabino-furanose was prepared by 1,4-addition of hydrazoic acid to disilylated α,β-unsaturated aldehyde followed by acetylation

Preparation of 2-azido-2-deoxypentose derivatives.

Abstract: 2-Azido-2-deoxypentose derivatives having D-xylo and L-arabino configurations were prepared via azidonitration of 1,5-anhydro-2-deoxypent-1-enitols, that is, xylal and arabinal derivatives, respectively. The L-ribo isomer was prepared by substitution of 2-trifluoromethylsulfonyloxy and 2-(1-imidazolylsulfonyloxy) group with azide. The D-xylo isomer was converted into the corresponding D-ribo and D-lyxo isomers.