Chapter SRP, Problem 25P

Consider this reaction involving peracetic acid:

These are spectral data for the product, B:

$\begin{array}{l}MS\left(m/z\right):150\left(\text{M}{\cdot }^{+}\right),132\hfill \\ \begin{array}{l}IR\left({\text{cm}}^{-1}\right):3400\left(\text{broad}\right),750\left(\text{no absorption in the range of }690–710\right)\\ {}^1\text{H NMR }\left(\delta \right):6.7–7.0\left(\text{m},4\text{H}\right),4.2\left(\text{m, 1H}\right),3.9\left(\text{d, 2H}\right),2.9\left(\text{d, 2H}\right),\text{ and }1.8\left(1\text{H};{\text{ disappears after treatment with D}}_{\text{2}}\text{O}\right)\\ {}^{13}\text{C NMR }\left(\delta \right):159\left(\text{C}\right)\text{, 129 }\left(\text{CH}\right)\text{, 126 }\left(\text{CH}\right)\text{, 124 }\left(\text{C}\right)\text{, 120 }\left(\text{CH}\right)\text{, 114 }\left(\text{CH}\right)\text{, 78 }\left(\text{CH}\right)\text{, 70 }\left({\text{CH}}_{\text{2}}\right),\text{ and 35 }\left({\text{CH}}_{\text{2}}\right)\end{array}\hfill \end{array}$ (a) What is the structure of B?

(b) Propose a mechanism for formation of B.