2-alkyl cyclohexenones are powerful intermediates for organic synthesis. The Wittig reaction of a series of aliphatic aldehydes with (cyclopropylmethyl)triphenylphosphonium bromide delivered the corresponding alkenyl cyclopropanes. UV radiation in the presence of Fe(CO)5 converted the alkenyl cyclopropanes to the 2-substituted cyclohexenones. Reaction with Mander's Reagent and methylation enabled a four-step synthesis of the tricyclic ketone that was the key intermediate in the Bachmann-Miescher estrone synthesis.