DL-apiose substituted with stable isotopes: synthesis, n.m.r.-spectral analysis, and furanose anomerization.
The branched-chain pentose DL-apiose has been synthesized in good yield by a new and simple chemical method that can be adapted to prepare (1-13C)-, (2-13C)-, (1-2H)- and/or (2-2H)-enriched derivatives. N.m.r. spectra (1H- and 13C-) have been interpreted with the aid of selective (13C)- and (2H)-enrichment, and 2D and 13C[13C]-n.m.r. spectra. The solution composition of DL-(1-13C)apiose in 2H2O, determined by 13C-n.m.r. spectroscopy, has been found to differ from that determined previously by 1H-n.m.r. spectroscopy. Several 13C-1H and 13C-13C couplings have been measured and interpreted in terms of apiofuranose ring conformation. Ring-opening rate-constants of the four apiofuranoses [3-C-(hydroxymethyl)-alpha- and -beta-D-erythrofuranose, and 3-C-(hydroxymethyl)-alpha- and -beta-L-threofuranose] have been determined by 13C-saturation-transfer n.m.r. spectroscopy, and compared to those obtained previously for the structurally related tetrofuranoses.
Snyder
J R
JR
Department of Chemistry, University of Notre Dame, Indiana 46556.
Serianni
A S
AS
D002236:Carbohydrate Conformation; D002247:Carbon Isotopes; D003903:Deuterium; D006859:Hydrogen; D007553:Isotope Labeling / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D010429:Pentoses / Q000138:chemical synthesis*; D011865:Radioisotope Dilution Technique
D002247:Carbon Isotopes; D010429:Pentoses; D006859:Hydrogen; D003903:Deuterium; C004983:apiose