Simple Access to Oxaadamantanes

Oxaadamantane and its derivatives are molecules of considerable interest to chemists and biologists, but until recently there was no convenient route to such compounds. Such a route has now been discovered, starting from the readily accessible 2-hydroxy-2-methyladamantane 1. Thus, oxidation of 1 by trifluoroperacetic acid in TFA at 20°C for one hour gave a mixture (actual yield not given merely described as a good yield ) of three products oxaadamantane 2 (56%), exo-4-hydroxy-2-oxaadamantane 3 (40%) and the lactone 4 (4%). 

Suggest mechanisms to account for the formation of 2,3 and 4. Note that oxaadamantane 2 is stable under the reaction conditions, and does not serve as a precursor to the hydroxy derivative 3. 

---