Two new useful methods for the preparation of diol 1 starting from available compounds are described. Separation of the two enantiomers entails resolutin of racemic diol 1 via the corresponding diastereomeric N-methylated phosphorothioamidates. Their separation by recrystallization followed by reduction afforded diol (aS)-1 and (aR)-1 in 100% and 72% ee, respectively.