The NMR spectroscopic kinetic measurements were performed by first making two stock solutions of DABCO (412.5 mg in 1 mL CD 3 OD, concentration: 3.68 M) and 4-nitrobenzaldehyde (183.4 mg in 2 mL CD 3 OD, concentration: 0.607 M). 4-Nitrobenzaldehyde was difficult to get into solution, and it was required to sonicate for a couple of minutes combined with waiting for 24 hours to allow equilibration of the reaction between the aldehyde and methanol to form the more soluble hemiacetal. To the 4-nitrobenzaldehyde solution, cyclohexane (22 µL) was added as an internal standard.