Pseudoephedrine has been used as a chiral auxiliary in diastereoselective alkylation reactions, providing easy access to enantiomerically enriched carboxylic acids, alcohols, ketones, and aldehydes. Because pseudoephedrine can be transformed into methamphetamine and other illegal drugs, many countries restrict or ban its sale and distribution, which can complicate its use in academic and industrial settings. This thesis shows that (1S,2S)-2-methylamino-1,2-diphenylethanol and (1R,2R)-2-methylamino-1,2- diphenylethanol (synonymously, (1S,2S)- and (1R,2R)-pseudoephenamine 30, respectively) enable a broad range of utilities in asymmetric synthesis that meet or exceed those that previously characterized the pseudoephedrine system alone, with several advantages. First, these auxiliaries are free from regulatory restrictions and are not known to be transformable into illegal substances; second, asymmetric alkylation reactions that employ pseudoephenamine as a chiral auxiliary proceed with equal or greater diastereoselectivities than the corresponding reactions employing pseudoephedrine, with notable improvements in the selectivities of the alkylation reactions that form quaternary carbon stereocenters; and lastly, amides derived from pseudoephenamine exhibit a greater propensity to be crystalline compounds than the corresponding pseudoephedrine derivatives. / Chemistry and Chemical Biology

Pseudoephedrine is well established as a chiral auxiliary in the alkylation of amide enolates to form tertiary and quaternary carbon stereocenters. However, due to its facile transformation into the illegal narcotic methamphetamine, pseudoephedrine is either illegal or highly regulated in many countries, which limits its use in academic and industrial settings. To address this issue, pseudoephenamine has been developed as a replacement for pseudoephedrine in organic synthesis. This new auxiliary suffers no regulatory issues and exhibits several practical advantages over pseudoephedrine, including the high diastereoselectivities observed in alkylation reactions forming quaternary carbon stereocenters, the propensity for pseudoephenamine amides to be free-flowing crystalline solids, and the sharp, well-defined peaks that typically compose the 1H NMR spectra of these amides. / Chemistry and Chemical Biology