The work of this thesis is in two parts. The first is concerned with the problem of producing the perfume base, muscone, from inexpensive, readily available precursors. Previously it had been shown that zero-valent nickel complexes would cyclotrimerise butadiene; an intermediate in the reaction being a twelve carbon bis π-allyl complex. The object of the work was to attempt to use this intermediate to produce a fifteen membered carbocycle which could readily be converted into muscone or some other related compound. The preparation and characterisation of the intermediate is described, together with the experimental approach to the problem. Although the work was not successful in producing significant amounts of a fifteen-membered carbocycle, some insight was gained into the reactivity of the π -allyl groups. The second part of the thesis is concerned with bonding modes and hydrogen shifts in cycloheptatriene complexes with transition metals. The preparation and characterisation of the previously unknown h1 , h2 complex, cycloheptatriene rhodium acetylacetonate, is described, together with some of its reactions. Hydrogen shifts in this compound are considered and compared with those in cycloheptatriene iron tricarbonyl and in both cases appears to be non-specific. The complexes are also considered as offering possible routes for the synthesis of [2H7] and [2H8] cycloheptatriene.