Reliable procedures are given for the preparation and purification of hexahydroxybenzene (benzenehexol), tetrahydroxy-p-benzoquinone, rhodizonic acid, triquinoyl (cyclohexanehexone), croconic acid, and leuconic acid (cyclopentanepentone). Certain derivatives and color tests, as well as infrared and ultraviolet spectra, are reported for their identification.