Synthesis of Brexan-2-one and Ring-Expanded Congeners

Article abstract of DOI:10.1021/jo00046a015

We report an efficient eight-step synthesis (26percent overall yield) of brexan-2-one (tricyclo<4.3.0.0.^3,7>nonan-2-one, 12).This ketone then served as a convenient precursor to the mechanistically useful molecules, homobrexan-2-one (tricyclo<5.3.0.0^4,8>decan-2-one, 14> and homobrexene (tricyclo<5.3.0.0^4,8>dec-2-ene, 20).Several homologation sequences for the preparation of 14 were developed and can be easily adapted to allow selective introduction of (13)C and (2)H labels in 14 and 20 for various mechanistic studies.