Studies of organic reations on alumina

The reactions of a series of terminal dibromoalkanes with S^-2 on AI₂O₃ were examined. The use of γ-alumina as a solid support for the macrocyclization reactions appeared to be a viable procedure to the more traditional high dilution technique in solution. In addition, cyclization reactions were performed with thioacetamide on activated and unactivated aluminas. Experiments were also carried out to study the characteristics of alumina of various activity and modified aluminas such as BBX₃/AI₂O₃ and CCI₄/AI₂O₃. Alumina was treated with CCI₄ to determine the number of O^-2 anions on the surface of alumina. Qualitative and quantitative measurements were taken to determine the acidity of these aluminas. Boron tribromide (BBr₃), a Lewis acid, was adsorbed on alumina and experiments were carried out to study the effect of joint participation of BBr₃/Al₂O₃ on the Diels-Alder reactions.