In alkene is treated with  \text{OsO}_4" id="MathJax-Element-2-Frame" role="presentation" style="position: relative;" tabindex="0"> \text{OsO}_4" id="MathJax-Element-3-Frame" role="presentation" style="position: relative;" tabindex="0">$\text{OsO}_4$ $\text{OsO}_4$ $\text{OsO}_4$ followed by H2​O2​. When the resulting diol is treated with HIO4​, the only product obtained is an substituted cyclic ketone with the molecular formula C_10​H₁₉O₂. What is the structure of the alkene?