The melting point phase diagrams of glycidyl tosylate (1), glycidyl 3-nitrobenzenesulfonate (2), and trans-3-methylglycidyl tosylate (3) have been investigated. Compounds 1 and 2 are found to exhibit a more significant solid solution behavior in the terminal zones of the phase diagram than 3, and are therefore more difficult to enrich enantiomerically by recrystallizations. The crystallization of 2 in ethanol is further complicated by polymorphism which can be followed by differential scanning calorimetry. The effects of these properties on the optical purification of 1-3 are discussed.