In chemistry, prochiral molecules are those which can be converted from achiral to chiral in a single step. If two identical substituents are attached to an sp3-hybridized atom, the descriptors pro-R and pro-S are used to distinguish between the two. Promoting the pro-R substituent to higher priority than the identical alternative would result in an R chirality center at the original sp3-hybridized atom, and vice versa. A trigonal planar sp2-hybridized atom can be converted to a chiral center wh… (More on Prochiral)