The synthesis of novel polyhydroxylated quinolizidines and azaspiro[4.5]decanes is reported. A key step of this transformation involved an addition of allylmagnesium bromide to an ω-bromonitrile derived from D-xylose followed by an intramolecular displacement of a bromide. The resulting cyclic imine was treated either with allylmagnesium bromide or with NaBH4, to provide 2,2-diallyl- or 2-allylpiperidine, respectively. The desired bicyclic framework was constructed via a ring-closing metathesis reaction. The Ru catalysts were reused in the following syn-dihydroxylation step.
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http://dx.doi.org/10.1021/ol403063v | DOI Listing |
Org Biomol Chem
December 2018
Natural Products Research Centre, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu, China.
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.
View Article and Find Full Text PDFJ Org Chem
September 2017
Univ. Grenoble Alpes, DCM and CNRS, DCM, F-38000 Grenoble, France.
Polyhydroxylated quinolizidines bearing a hydroxymethyl group at the ring junction were synthesized from a readily available l-sorbose-derived ketonitrone. Evaluated as glycoside hydrolase inhibitors, these quinolizidines revealed to be potent and selective α-glucosidase inhibitors. Quinolizidine 9a is the first quinolizidine-scaffolded iminosugar exhibiting nanomolar inhibition of a glycoenzyme.
View Article and Find Full Text PDFJ Org Chem
November 2014
Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52, 01-224 Warsaw, Poland.
A direct approach to the synthesis of indolizidine and quinolizidine scaffolds of iminosugars is described. The presented strategy is based on a one-pot sugar lactam reduction with Schwartz's reagent followed by a diastereoselective Mannich/Michael tandem reaction of the resulting sugar imine with Danishefsky's diene. The stereochemical course of the investigated reaction has been explained in detail.
View Article and Find Full Text PDFOrg Lett
December 2013
Institute of Organic Chemistry, Polish Academy of Sciences , Kasprzaka 44/52, 01-224 Warsaw, Poland, and Institute of Physical Chemistry, Polish Academy of Sciences , Kasprzaka 44/52, 01-224 Warsaw, Poland.
The synthesis of novel polyhydroxylated quinolizidines and azaspiro[4.5]decanes is reported. A key step of this transformation involved an addition of allylmagnesium bromide to an ω-bromonitrile derived from D-xylose followed by an intramolecular displacement of a bromide.
View Article and Find Full Text PDFOrg Biomol Chem
August 2012
Dept Biological Chemistry and Molecular Modeling, Instituto de Química Avanzada de Cataluña, IQAC-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
The synthesis, conformational study and inhibitory properties of diverse indolizidine and quinolizidine iminocyclitols are described. The compounds were chemo-enzymatically synthesized by two-step aldol addition and reductive amination reactions. The aldol addition of dihydroxyacetone phosphate (DHAP) to N-Cbz-piperidine carbaldehyde derivatives catalyzed by L-rhamnulose 1-phosphate aldolase from Escherichia coli provides the key intermediates.
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