Underivatized enantiomers of a beta -amino alcohol compound are directly separated by means of a chiral selector compound having the formula I wherein R2 and R3 are each independently lower alkyl, preferably methyl; R4 and R5 are each independently NO2, N(R6)3+, CN, COOR2, SO3H or COR8, preferably NO2; R6, R7 and R8 are each independently hydrogen or lower alkyl, preferably hydrogen or methyl, W is H or CH=CH2, X and Y are each independently OR9 or NR10R11, preferably X and Y are the same and most preferably X and Y are each OR9, or X and Y together with the P to which they are attached form a 5- or 6-membered ring having the formula R9, R10, R11 and R12 are each independently hydrogen or lower alkyl, R9 is preferably methyl, R10, R11 and R12 are preferably hydrogen or methyl, Z is O or NH, n is 1 to 20, preferably 1 to 8 when W is H, and 1 to 3 when W is CH=CH2, and m is 1 or 2, said compound being an R or an S enantiomer or a mixture of R and S enantiomers.