A robust synthetic approach to cis-γ-hydroxycarvone derivatives has been developed, enabling efficient access to synthetic building blocks for the growing family of bioactive sesterterpenoid natural products. Using this approach, an allyl bromide carvone derivative was used as the key building block for the total synthesis of the natural product phorbin A. This synthetic sequence also demonstrates the utility of benozyl enol ethers as an effective means of masking a β-ketophosphonate and their subsequent application in a one-pot benzoyl transfer-intramolecular Horner-Wadsworth-Emmons reaction.