A trisubstituted compound ‘A’ ${\mathrm{C}}_{10}{\mathrm{H}}_{12}{\mathrm{O}}_2$ gives neutral FeCl₃ test positive. Treatment of compound ‘A’ with NaOH. and CH₃Br gives C₁₁H₁₄O₂,with hydroidic acid gives methyl iodide and with hot conc. NaOH gives a compound B. ${\mathrm{C}}_{10}{\mathrm{H}}_{12}{\mathrm{O}}_2$ .compound ‘A’ also decolorizes alkaline KMnO₄.the number of $\pi$ bonds present in the compound ‘A’ is _______