Pérez-Estrada, S.; Joseph-Nathan, P.; Jiménez-Vázquez, H. A.; Medina-López, M.; Ayala-Mata, F.; Zepeda, L. G. ?Diastereoselective Preparation of New (R)- and (S)-2-Methoxy-2-phenyl-pent-3-ynoic Acids and Their Use as Highly Reliable Chiral Derivatizing Agents? J. Org. Chem. 2012, 77, 1640-1652, DOI: 10.1021/jo2016554.
Benzoyl-S,O-acetals 1a and 1b were used as chiral auxiliaries to achieve the diastereoselective preparation of both enantiomers of 2-methoxy-2-phenylpent-3-ynoic acids (MPPAs). The latter were condensed with several chiral secondary alcohols and some primary amines to evaluate their potential as chiral derivatizing agents (CDAs). The 1H NMR spectra of the corresponding esters and amides showed strong consistency with the absolute configuration of the carbinol and amine moieties, whose observed ??L1 and ??L2 values were in the ranges of 0.1?0.4 and 0.02?0.12 ppm, respectively.