A simple and unambiguous route to adamantene: debromination of 1,2-dibromoadamantane with bis(trimethylsilyl)mercury

Abstract

In a process extensible, in principle, to the preparation of other anti-Bredt alkenes, reaction in boiling benzene of 1,2-dibromo- or 1,2-di-iodo-adamantane with bis(trimethylsilyl)mercury, which dehalogenates 1,2-dibromoalkanes in a concerted, ‘four-centre’ manner, leads to the unambiguous generation of adamantene, as shown by trapping by 1,3-diphenylisobenzofuran (30–35% yield of adduct) and 2,5-dimethylfuran (16% yield of adduct).