Chiral compounds:
What is Chiral?
Chiral means hands in Greek, which are symmetrical like right and left hands.  Chiral is also referred to as enantiomer.  Although these isomers have the same chemical structural formula and physicochemical features, if the polarized light is irradiated through the enantiomer, one of them turns the light to the right and the other turns the light to the opposite direction, the left.
Because of its optically opposite feature, it is called as enantiomer or chiral building block.
A compound that contains an asymmetric center (chiral atom or chiral center) and thus can occur in two nonsuperimposable mirror-image forms (enantiomers).
The term "chiral" in chemistry is used to describe something that is non-superimposible on its mirror image in 3 dimensions. For example, if you put your hands together, you will notice that the general shapes match up in location, but the details do not. Try wearing a left handed glove on your right hand, for instance; you'll see that the general shape is similar, but the glove will not fit properly. Human hands are "Chiral". Similarly, most molecules are chiral because they will not fit properly onto a mirror image.
what’s the chiral synthesis?
Chiral synthesis is also called asymmetric Synthesis, enantioselective synthesis or stereoselective synthesis, is organic synthesis which introduces one or more new and desired elements of chirality.[1][2] This is important in the field of pharmaceuticals because the different enantiomers or diastereomers of a molecule often have different biological activity.