The synthesis of 3-mono-O-ethyl cellulose (EC) via 2,6-di-O-thexyldimethylsilyl cellulose was studied. Treatments with tetrabutylammonium fluoride trihydrate lead to the complete cleavage of the protective group. The structure of the polymer was confirmed by means of one- and two dimensional NMR spectroscopy. 3-mono-O-EC is soluble both in aprotic-dipolar organic media and water and shows thermoreversible gelation. A gelation temperature of 58.5 degrees C was found, which is about 30 degrees C higher than the cloud point temperature of conventional water soluble EC.