TY - JOUR
T1 - Conformations of the d-glucarolactones and d-glucaric acid in solution
AU - Horton, Derek
AU - Wałaszek, Zbigniew
N1 - Funding Information:
*This work was supportedb y NSF grant No. MPS72-04609-A01 (O.S.U.R.F. Project 3443-Al). *For a preliminary report, see ref. 1. Alto whom inquiries should be addressed. **Present address:I nstituteo f Oncology, Departmento f Tumor Biology, 44-100 Gliwice, Poland.
PY - 1982/7/1
Y1 - 1982/7/1
N2 - The conformations of d-glucaric acid (1), d-glucaro-1,4-lactone (2), d-glucaro-6,3-lactone (3), and d-glucaro-1,4:6,3-dilactone (4) in solution were investigated by 1H-n.m.r. and 13C-p.F.t., n.m.r. spectroscopy. The solvents used were deuterium oxide, methanol-d4, and dimethyl sulfoxide-d6, and praseodymium chloride was employed as a lanthanide shift-reagent. For 2, it was found that the conformational equilibrium 3E(d) {A figure is presented} E3(d) exists in solution, and that the OH-5 group tends to occupy the position over the lactone ring in the favored E3(d),gg conformation. The n.m.r. data for 3 indicated that the conformational equilibrium is shifted in favor of the 4E(d) {A figure is presented} E4(d),gt conformation in solution. The dienvelope conformation 3E:E4(d) was found to be the favored conformation of 4. For 1, a conformational equilibrium between one planar, zigzag form and two sickle forms was indicated by the n.m.r. data observed. 13C-N.m.r. spectroscopy proved to be a convenient method for monitoring the lactonization of 1, and the hydrolysis of its lactones. Lactones other than 2-4 were not found in solutions prepared from 1-4, either during their mutarotation or after equilibration at 30°.
AB - The conformations of d-glucaric acid (1), d-glucaro-1,4-lactone (2), d-glucaro-6,3-lactone (3), and d-glucaro-1,4:6,3-dilactone (4) in solution were investigated by 1H-n.m.r. and 13C-p.F.t., n.m.r. spectroscopy. The solvents used were deuterium oxide, methanol-d4, and dimethyl sulfoxide-d6, and praseodymium chloride was employed as a lanthanide shift-reagent. For 2, it was found that the conformational equilibrium 3E(d) {A figure is presented} E3(d) exists in solution, and that the OH-5 group tends to occupy the position over the lactone ring in the favored E3(d),gg conformation. The n.m.r. data for 3 indicated that the conformational equilibrium is shifted in favor of the 4E(d) {A figure is presented} E4(d),gt conformation in solution. The dienvelope conformation 3E:E4(d) was found to be the favored conformation of 4. For 1, a conformational equilibrium between one planar, zigzag form and two sickle forms was indicated by the n.m.r. data observed. 13C-N.m.r. spectroscopy proved to be a convenient method for monitoring the lactonization of 1, and the hydrolysis of its lactones. Lactones other than 2-4 were not found in solutions prepared from 1-4, either during their mutarotation or after equilibration at 30°.
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U2 - 10.1016/S0008-6215(00)81857-1
DO - 10.1016/S0008-6215(00)81857-1
M3 - Article
AN - SCOPUS:0001793724
VL - 105
SP - 95
EP - 109
JO - Carbohydrate Research
JF - Carbohydrate Research
SN - 0008-6215
IS - 1
ER -