Abstract: This invention is directed to novel ether compounds of formula (I) ##STR1## which are of value in medicine in the palliation of haemoglobinopathies, in particular sickle-cell anaemia, and also in the palliation of pulmonary dysfunction, protection from the effects of hypoxia and the radio-sensitization of tumors. The invention is also directed to methods for the preparation of the ether compounds, to pharmaceutical formulations containing them, the preparation of such formulations and the use of the compounds in human medicine. Also provided by the invention are intermediates of value in the preparation of the ether compounds, by the methods described, and the preparation of the intermediates.