Cyclic ketals of tartaric acid: simple and tunable reagents for the determination of the absolute configuration of primary amines.

2,2-Diphenyl-[1,3]dioxolane-4,5-dicarboxylic acid (DPD) and 2,2-dinaphthalen-2-yl-[1,3]dioxolane-4,5-dicarboxylic acid (DND) have been synthesized starting from dimethyl tartrate. DPD and DND amides of alpha-chiral primary amines showed significantly different (1)H chemical shift values depending on the stereochemistry of the derivatizing agent. On the basis of this chemical shift difference, the absolute configuration of amine substrates could be assigned. DND amides showed significantly larger chemical shift differences than the corresponding DPD amides allowing for a more error-free assignment.