Synthesis and structure of 6-amino-2,3,6-trideoxy-D-erythro-hexono-1,6-lactam and 6-amino-3,6-dideoxy-D-xylo-hexono-1,6-lactam.
Solid-state conformations of 6-amino-2,3,6-trideoxy-D-erythro-hexono-1,6-lactam (3a) and 6-amino-3,6-dideoxy-D-xylo-hexono-1,6-lactam (7a) were determined using X-ray diffraction. Conformations of the compounds 3a, 7a, and their per-O-acetyl derivatives 4,5-di-O-acetyl-6-amino-2,3,6-trideoxy-D-erythro-hexono-1,6-lactam (3b) and 2,4,5-tri-O-acetyl-6-amino-3,6-dideoxy-D-xylo-hexono-1,6-lactam (7b) in solutions were deduced from the analysis of NMR spectra using a modified Karplus equation and compared with the results of circular dichroism measurement of lactams 3a and 7a. Conformation 4C(1,N) was revealed for solid lactams 3a and 7a and for lactams 7a and 7b in solution, while lactams 3a and 3b in solution exist in the approximately 1:1 equilibrium of the conformers 4C(1,N) and (1,N)C4.
Hamerníková
M
M
Department of Chemistry of Natural Compounds, Institute of Chemical Technology, Prague, Czech Republic.
Pakhomova
S
S
Havlícek
J
J
Votavová
H
H
Kefurt
K
K
D002236:Carbohydrate Conformation; D002942:Circular Dichroism; D003837:Deoxy Sugars / Q000138:chemical synthesis; D006601:Hexoses / Q000138:chemical synthesis*; D006860:Hydrogen Bonding; D007769:Lactams / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D014961:X-Ray Diffraction
D003837:Deoxy Sugars; D006601:Hexoses; D007769:Lactams