Conversion of 1,2-dione to a 7 membered oxepane?

Has anyone heard of forming a seven membered ring from the rearrangement of a 1,2-dione? What I am talking about specifically is benzil rearrangement:
[![benzil to 7 membered ring](https://i.stack.imgur.com/yeSiG.png)](https://i.stack.imgur.com/yeSiG.png)
Could anyone give me guidance for how on earth something like this would form? 




By this late date Coherent has probably resolved the structure of his product (**9**). From the limited information provided, it appears that a photolysis of benzil (**1**) was conducted in hydroxylic solvent (methanol?). Let's assume for the sake of argument that the product has the structure that Coherent has proposed. Coherent asks, how can it (**9**) be formed? First of all, hydroxyl radicals need not be invoked. Structure **2** represents an excited state of benzil that may cyclize to diradical **3** whose resonance structure is diradical **4**. Rearomatization of **4** provides enol **5**, tautomerization of which affords 2-phenylbenzofuran-3-one (**6**). Now the reorganization **4** --> **5** need not be intramolecular as indicated (red hydrogen) but intermolecular or, less likely, via the solvent acting as a source of hydrogen atoms (methanol C-H bond DHo = 96 kcal/mol. Probably too strong a C-H bond to deliver a hydrogen atom to stabilized radicals).  
  

Benzofuranone **6** is a known compound. If benzofuranone **6** is truly formed in the reaction sequence, it should independently afford the final product **9** upon irradiation conditions. Cleavage of benzofuranone **6** by the Norrish type I mechanism leads to diradical **7**, which may recyclize to **8** and subsequently rearomatize to **9**. [I am not overly excited about going from a 5-membered to a 7-membered ring, but then again who knows.]  
  

Finally, compound **9** should be able to be synthesized from O-benzylsalicylic acid by intramolecular acylation.


[![enter image description here](https://i.stack.imgur.com/QwA20.jpg)](https://i.stack.imgur.com/QwA20.jpg)


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