New methods of resolution and purification of racemic and diastereomeric amino alcohol derivatives using boric acid and chiral 1,1 '-bi-2-naphthol

Resolution of the racemic amino alcohol derivatives 1-6 is readily achieved to obtain enantiomerically enriched compounds using chiral 1,1 ' -bi-2-nap hthol and boric acid in solvents such as CH3CN, THF, and MeOH. Purification of the diastereomeric mixture 7 has also been carried out following this m ethod. The corresponding intermediate ammonium berate complexes were also c haracterized by X-ray diffraction methods.