The oligoalumosiloxanes {[Ph2SiO]8[Al(O)OH]4∙2,5Et2O∙HOtBu} (6) and {[Ph2SiO]8[Al(O)OH]4∙2Et2O∙2HOiPr} (7) have been obtained from the reaction of diphenylsilanediol with aluminium-tri-tert-butoxide and aluminium-tri-iso-propoxide in ethyl ether with reasonable yields. In a 1:1 molar mixture of toluene and the respective alcohol (iso-propanol ortert-butanol), the ethyl ether molecules in {[Ph2SiO]8[Al(O)OH]4∙4Et2O}, in6or7can be completely displaced forming the compounds [Ph2SiO]8[Al(O)OH]4∙4HOiPr (8) and [Ph2SiO]8[Al(O)OH]4∙nHOtBu (9). Whereas6,7and8are crystalline,9is obtained as a viscous liquid. An X-ray structure determination on {[Ph2SiO]8[Al(O)OH]4∙3Et2O∙HOtBu} reveals different bonding modes of the diethyl ether molecules to the oligoalumosiloxane compared to the tert-butanol, which forms two hydrogen bonds (one to the OH-group of the inner Al4(OH)4cycle and one through the alcohol OH-group to a Si-O-Al moiety The alcohol adducts have been characterized in solution through1H-,13C- and29Si-NMR and show dynamic equilibria between the oligoalumosiloxane [Ph2SiO]8[Al(O)OH]4and the alcohol molecules.