Used as a protected form of 4-hydroxycyclohexanone in organic synthesis, particularly in multi-step reactions where selective protection of ketone functionality is required. The dioxaspiro acetal group stabilizes the ketone during transformations elsewhere in the molecule, while the tosylate serves as a good leaving group for nucleophilic substitution or elimination reactions. Commonly employed in the synthesis of complex natural products and pharmaceuticals to control reactivity and regioselectivity. After desired transformations, the acetal can be deprotected under mild acidic conditions to regenerate the ketone.