Identify the product of this reaction and propose a mechanism for its formation.
$$
\begin{gathered}
\mathbf{B}, \mathbf{C}_{\mathbf{8}} \mathbf{H}_{\mathbf{1 4}} \mathbf{O}_{\mathbf{3}} \\
v_{\max }\left(\mathrm{cm}^{-1}\right) 1745,1730 \\
\delta_{\mathrm{c}} \text { (p.p.m.) } 202,176,62,48,34,22,15 \\
\delta_{\mathrm{H}} \text { (p.p.m.) } 1.21(6 \mathrm{H}, \mathrm{~s}), 1.8(2 \mathrm{H}, \mathrm{t}, J 7 \mathrm{~Hz}), \\
2.24(2 \mathrm{H}, \mathrm{t}, J 7 \mathrm{~Hz}), 4.3(3 \mathrm{H}, \mathrm{~s}), 10.01(1 \mathrm{H}, \mathrm{~s})
\end{gathered}
$$