Simultaneous determination of enantiomeric purity and erythro/threo relationship in chiral 1,2-aminoalcohols by NMR using (R)-(+)-t-butylphenylphosphinothioic acid

Abstract The rapid simultaneous determination of enantiomeric purity and erythro / threo relationship for a series of chiral 1,2-aminoalcohols is reported. Complexation with 1 equivalent ( R )-(+)- t -butylphenylphosphinothioic acid results in a preferred conformation of the aminoalcohol which in turn causes the interproton dihedral angle to assume either large ( threo ) or small ( erythro ) J values. Measurement of the resulting vicinal coupling constant allows easy and rapid assignment of erythro versus threo .