The treatment of isoprene [CH2==C(CH3)CH==CH2] with one equivalent of mCPBA forms A as the...

The treatment of isoprene [CH2==C(CH3)CH==CH2] with one equivalent of mCPBA forms A as the major product. A gives a molecular ion at 84 in its mass spectrum, and peaks at 2850–3150 cm−1 in its IR spectrum. The 1H NMR spectrum of A is given below. What is the structure of A ?