We previously reported on the synthesis of stereoisomerically pure O-isobutyl lactol I via low-temperature (–70°C) treatment of lactone II with 2 equiv (or more) of diisobutylaluminum hydride in methylene chloride and proposed a probable scheme of this reaction [1]. In the present communication we present new examples of synthesis of O-isobutyl derivatives III and IV from lactones V and VI, respectively, under analogous conditions. These examples demonstrate unusual behavior of diisobutylaluminum hydride in reactions with seven-membered lactones in methylene chloride. Low-temperature (–70°C) hydride reduction of lactones II, V, and VI in such solvents as toluene and tetrahydrofuran quantitatively afforded the corresponding lactols. Reduction of lactones V and VI (general procedure). A solution of 11.8 mmol of lactone V [2] or VI [3] in 20 ml of anhydrous methylene chloride was ISSN 1070-4280, Russian Journal of Organic Chemistry, 2011, Vol. 47, No. 3, pp. 472–473. © Pleiades Publishing, Ltd., 2011. Original Russian Text © G.Yu. Ishmuratov, V.A. Vydrina, M.P. Yakovleva, E.F. Valeeva, R.R. Muslukhov, G.A. Tolstikov, 2011, published in Zhurnal Organicheskoi Khimii, 2011, Vol. 47, No. 3, pp. 471–472.