Daphnepapytone A is an unprecedented caged guaiane sesquiterpenoid with α-glucosidase inhibitory activity. We describe progress toward its total synthesis using an α-santonin-type rearrangement strategy. In the course of these studies, a range of guaiane frameworks, including daphbolides A and B, were prepared. However, attempted C9 oxidations of the guaiane proved problematic. Notably, some decalin substrates underwent unexpected rearrangements to yield phenolic products, revealing novel reactivity patterns in this compound class.