A series of new N-alkyl-3-hydroxypiperidine derivatives containing a five-membered hemiketal were synthesized from 1-C-acetylmethyl sugars. Based on the stereochemistry of the products obtained, a plausible mechanism is illustrated. A new approach to the hemiketal, which has undergone hydrogenation in the presence of Pd/C and beta-elimination and intramolecular cycloaddition with 1% NaOMe in methanol
A mild and effective method for the synthesis of polyhydroxylated quinolizidine iminosugars is described. The Mannich-type reaction of iminosugar C-glycosides with aldehyde in the presence of L-proline-Et3N provides polyhydroxylated quinolizidine iminosugars, and desired products as the potential glucosidase inhibitors were obtained in good to excellent yields with excellent stereoselectivity.
synthesized and tested for α-glucosidase inhibition. The results suggested that 6e is a promising and potent α-glucosidaseinhibitor. Enzymatic kinetic assays indicated that compound 6e may be classified as an uncompetitive inhibitor. The study of structure-activity relationships of those iminosugars provided a starting point for the discovery of new α-glucosidaseinhibitors.