Department of Chemstry, Southern University, New Orleans, Louisiana 70126, U.S.A. Manuscript received 13 November 1976, accepted 10 February 1977 Preparation or Aluminum tert.-alkoxides and their corresponding mixed mono- isopropoxide di-tert.-alkoxides by alcohol interchange between aluminum isopropoxide and the appropriate tert.-alcohol is successfully carried out. Starting from tert.- butoxide the higher alkoxides are prepared even more suitably by the interchange method. The preparation of mono-isopropoxide di-tert.-butoxide was standardized. The molecular weights of these newly prepared compounds were determined ebullioscopically, in benzene and toluene.