Enzymatic reactions can gain this property by binding to dirigent proteins. Catalysis of reactions with this property is often initiated by “privileged” ligands with C2 (“C-two”) symmetry as exemplified by DIPAMP. Proline (10[1])is used as an (10[1])organocatalyst to grant (10[1])this property to aldol condensations. (-5[1])Cram’s rule (10[1])and the Felkin–Anh model describe how nucleophilic attacks on carbonyls cause this property’s induction. (10[2])Reactions often maintain this property through the incorporation of “auxiliaries.” (10[1])The (-5[1])products of reactions with this property (10[1]-5[3])have nonzero optical rotation, (10[1]-5[1])while (-5[1])reactions (-5[1])without this property produce racemic (10[3]-5[2])mixtures. (10[1]-5[5])For 10 points, (-5[1])name this (-5[1])property of reactions (10[1])that preferentially form one (10[2])chiral (10[1])stereoisomer (10[1])over another. (10[1]0[1])■END■ (10[7]0[12])