The proton NMR of the C1 proton region of D-glucopyranose shows that both anomers are present. (The large peak in the middle is residual HDO in the H₂O solvent.) The integrals are given in arbitrary units.

(a) Which is the resonance of the a-anomer, and which is the resonance of the β-anomer? How do you know?

(b) How much of each anomer is present in the mixture?

Transcribed Image Text:

absorption 1720 5.4 1560 chemical shift, Hz 1500 integral = 596 J = 3.8 Hz 5.2 HDO 1440 1380 J = 7.9 Hz 5.0 4.8 chemical shift, ppm (8) integral = 1060 4.6 1320 4.4