Figure 3. 13C- and 2H-labeling study of model hemiformal production showing characteristic 1H NMR properties consistent with the previously reported NMR spectra of 1a and 1b24.
(A) CH3OCH2OH exhibits analogous peak positions as well as the characteristic O-H proton splitting pattern corresponding to those for 1a and 1b. (B) The 1H-13C decoupled spectrum corresponds to that of the product formed by bubbling 12CH2O in CH3OH (spectrum C). (D) Upon addition of D2O the hydroxyl resonance at 6.14 ppm diminished and the methylene protons at 4.53 ppm collapse to a singlet. (E) The full 1H spectrum of CH3OCH2OH/CH3OH in DMSO-d6, for completeness.