We recently discovered that cyclic γ-silyloxy-β-hydroxy-α-diazoesters (e.g. 1, R=OEt) undergo efficient ring fragmentation upon treatment with Lewis acids to provide tethered aldehyde ynoate products (e.g. 2). Ring fragmentations are useful synthetic transformations because they can provide structures that are not easily accessible by other means. Additionally, the fragmentation products typically contain two new functional groups linked at a predefined distance, which make these products versatile synthetic intermediates. Here we report that γ-silyloxy-β-hydroxy-α-diazoketones participate in an analogous fragmentation reaction to provide tethered aldehyde ynones upon treatment with tin tetrachloride. A variety of γ-silyloxy-β-hydroxy-α-diazoketones bearing different keto substituents have been tested and provided good to excellent yields of the ynone tethered aldehyde products. Although the fragmentation precursors may at first glance appear to be exotic species, they are easily prepared by simply adding lithiated α-diazoketones to α-silyloxy ketones. The α-diazoketones are, in turn, conveniently prepared from the corresponding acid chlorides by treatment with ethereal diazomethane. The mechanism of this fragmentation and our preliminary results for tethered aldehyde ynone product formation will be discussed.