Dimethylaluminium methoxide, isopropoxide, t-butoxide, and phenoxide have been prepared and were found to be stable with respect to disproportionation in benzene and in ether, and upon distillation, although dimethylaluminium methoxide disproportionated in tetrahydrofuran and pyridine. Only one of the methyl groups of trimethylaluminium could be exchanged for an isopropoxyl group of aluminium isopropoxide or methylaluminium diisopropoxide in non-polar solvent at moderate temperature; no exchange occurred in ether.