An efficient route towards a new branched tetrahydrofurane δ-sugar amino acid from a pyrolysis product of cellulose.
(1R,5S)-1-hydroxy-3,6-dioxa-bicyclo[3.2.1]octan-2-one, is a bicyclic lactone obtained in gram-scale by catalytic pyrolysis of the renewable source cellulose. Now it has been used as a chiral building block in the preparation of the new δ-sugar amino acid, (3R,5S)-5-(aminoethyl)-3-hydroxytetrahydrofurane-3-carboxylic acid, by an efficient synthesis in five steps with a 67% overall yield. The structure of this tetrahydrofurane amino acid, isolated in protonated form, was assigned by extensive mono- and bidimensional (1)H- and (13)C-NMR analysis and mass spectrometry, including measurements by electrospray and matrix-assisted laser desorption ionization techniques, the latter one for high-resolution experiments. This amino acid is an isoster of dipeptide glycine-alanine (H-Gly-Ala-OH), with a potential use in the access of new peptidomimetics with conformationally restricted structures due to the presence of tetrahydrofurane ring. As a preliminary study in order to disclose this effect, density functional theory calculation performed in water using polar continuum model was applied to the new amino acid and H-Gly-Ala-OH dipeptide, so that to evaluate and compare the relative torsional angles for the energy-minimized structures.
Defant
Andrea
A
Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Povo-Trento, Italy.
Mancini
Ines
I
Torri
Cristian
C
Malferrari
Danilo
D
Fabbri
Daniele
D
D000596:Amino Acids / Q000737:chemistry*; D000606:Amino Sugars / Q000138:chemical synthesis* / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry*; D015394:Molecular Structure
D000596:Amino Acids; D000606:Amino Sugars; D005663:Furans; D007783:Lactones; D002482:Cellulose