The reaction of dimethyl aluminum fluoride (Me 2 AlF, DMAF) with 2,6-diisopropylphenol and triethylcitrate, respectively, leads to the products (RO) 6 Al 4 F 2 Me 4 (R) 2,6-i-Pr 2 C 6 H 3) (1) and (ROAlFMe) 2 (R) C(CH 2 COOEt) 2 -(COOEt)) (2), containing Al 2 O 2 ring systems. Both aluminum-µ-oxo fluorides have been structurally characterized. Fluorine exchange in the reaction of 2,6-diisopropylphenol with DMAF has been monitored using 19 F NMR spectroscopy. The proposed processes in solution are confirmed by the solid-state structure of 1. Compound 1 contains four aluminum centers forming three four-membered ring systems. The two outer cycles consist of bridging -OR groups, whereas the aluminum atoms in the central cycle are connected via fluorine atoms. Two of the aluminum atoms are 4-fold coordinated, and two are 5-fold coordinated. Compound 1 contains a rare four-membered Al 2 F 2 ring system. Compound 2 exhibits a dimeric structure, with oxygen rather than fluorine atoms bridging the aluminum atoms. A further carboxy oxygen atom binds coordinatively to one aluminum atom in 2. The aluminum atoms are 5-fold coordinated. In search of an alternative approach to synthesizing Al 2 O 2 ring systems, it has been found that neither DMAF nor trimethyl aluminum (Me 3 Al, TMA) reacts with (Me 3 Si) 2 O, whereas the reaction of diisobutyl aluminum hydride (i-Bu 2 AlH, DIBAH) with (Me 3 Si) 2 O leads to (i-Bu 2 AlOSiMe 3) 2 (3). In compound 3 the aluminum centers in the four-membered Al 2 O 2 ring system are only 4-fold coordinated. This is the first example of a structurally characterized aluminum product obtained from (Me 3 Si) 2 O under cleavage of the Si-O bond.