Question

Can anyone explain to me in simple terms diasteromeric ratios and NMR I am so lost.

Answer 1

Lets say you expect two diastereomers in your NMR. Diastereomeric ratio, that is the ratio of two diastereomers can be found easily, by first identifying the proton at the chiral carbon which results in two configurations and hence two distereomers. Remember diastereomers have different chemical shifts or physical and chemical properties so they would appear at different places in NMR spectrum. Integrate these protons and take a ratio. As both will correspond to 1H, the integration ratio of them should reflect the exact ratio in which the two distereomers are present in the system.