The combined use of a catalytic amount of silver acetate and a stoichiometric amount of DBU efficiently catalyzed the incorporation of CO2 under mild reaction conditions into a wide range of propargylic alcohols bearing a terminal or an internal triple bond to afford the corresponding cyclic carbonates in high‐to‐excellent yields. All the cyclic carbonates obtained from the reaction were found to be single isomers. The geometries were determined to be (Z) by X‐ray crystal structure analysis and NOE experiments.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

A short synthesis of gabosine I (1) from delta-D-gluconolactone (3) in four steps, involving a one-pot TPAP oxidation-K2CO3-mediated intramolecular Horner-Wadsworth-Emmons (HWE) olefination as the key step, is described. Regioselective acetylation of the primary alcohol in gabosine I (1) then furnished gabosine G (2).

A pseudo-1,4'- N-linked disaccharide, pseudoacarviosin 5, was constructed via a key palladium-catalyzed coupling reaction of pseudoglycosyl chloride 8 (prepared from d-glucose via a novel direct intramolecular aldol addition in 12 steps) and pseudo-4-amino-4,6-dideoxy-alpha- d-glucose 9 (prepared from l-arabinose via an unusual trans-fused isoxazolidine-selective intramolecular nitrone-alkene cycloaddition in 11 steps). Pseudoacarviosin 5 has been shown to be a potent inhibitor of alpha-glucosidases, particularly the intestinal mucosal enzymes sucrase and glucoamylase of relevance to blood glucose control.

A new and stereoselective intramolecular direct aldol reaction of diketones derived from carbohydrates has been developed to construct carbocycles with D-gluco-, D-galacto-, D-manno-, and L-ido-configurations. The stereochemical outcome of the aldol reaction of the diketone is dependent on the base used. Transformation of D-gluco-aldols readily affords valiolamine which also constitutes a formal synthesis of voglibose. Facile conversion of D-gluco-cyclohexanones into validoxylamine G has been achieved in 12 steps with 15.1% overall yield from D-glucose.