Asymmetric Addition/Alkylation of Pseudoephedrine Amides

Significance

This work represents an elegant example of asymmetric tandem C-C bond formation reactions. It uses inexpensive pseudoephedrine, available in both enantiomeric forms as a chiral auxiliary. The diastereoselectivity is excellent (above 90%) in most described examples. The reaction proceeds well for β-alkylacrylic derivatives, and both alkyl- and phenyllithium may serve as nucleophiles. The products can be readily transformed into acids by hydrolysis or into the corresponding alcohols by the reduction with lithium aminoboranes.