D(+)-Melezitose crystallises from aqueous EtOH as the monohydrate and water as the dihydrate, and is then dried at 110o (anhydrous). It is also purified by dissolving in an equal volume of H2O, filtering into a crystallising dish and allowing to stand (loosely covered) for several weeks undisturbed at 20o. The crystals of clear prisms are wiped carefully and dried in air. They effloresce at once losing 3.35% of their weight, and after 3days in air the loss is for 1H2O from the dihydrate. Drying at 110o for 6hours in vacuo yields the anhydrous form which after 2days in air it absorbs H2O to give the monohydrate. The monohydrate is also obtained by dissolving it in an equal weight of H2O at 60o and adding 4 volumes of 95% EtOH and drying in air overnight. [Richtmeyer & Hudson J Org Chem 11 610 1946, Beilstein 17 III/IV 3815, 17/8 V 414.]
