This invention provides chiral nonracemic compound of formula: ##STR1## wherein n and m are 0 or 1, but one of n or m must be 1; k=0 or 1; B=COO or OOC; X.sub.1, X.sub.2, X.sub.3 and X.sub.4 are either H, an electron donor or an electron acceptor where at least one of the groups X.sub.1, X.sub.2, X.sub.3 or X.sub.4 is an electron acceptor and at least one of these groups is an electron donor and when one of X.sub.1 or X.sub.3 is an electron donor, the other is an electro a acceptor and when one of X.sub.2 or X.sub.4 is an electron donor, the other is an electron acceptor; and R.sub.1 and R.sub.2 can be various substituted and unsubstituted alkanes and monoalkenes. Compounds provided include those where one of R.sub.1 or R.sub.2 is a chiral non-racemic tail group, particularly a group selected from --O--C.sup.* H(CH.sub.3)R.sub.c, --O--C.sup.* H(CH.sub.3)COOR.sub.d, and --O--CH.sub.2 C.sup.* HF--C.sup.* HF--R.sub.2 in which the .sup.* indicates an asymmetric carbon enriched in one stereoconfiguration where R.sub.c, R.sub.d, and R.sub.e can be various substituted and unsubstituted alkanes and monoalkenes. The compounds of this invention are useful in the preparation of FLC mixtures and non-linear optical materials.