An organic compound $\left(\mathrm{P}\right)$ having molecular formula ${\mathrm{C}}_9{\mathrm{H}}_{10}\mathrm{O}$, form an orange precipitate $\left(\mathrm{Q}\right)$ with $2,4-\mathrm{DNP}$ reagent. Compound $\left(\mathrm{P}\right)$ gives a yellow precipitate $\left(\mathrm{R}\right)$ when heated in the presence of iodine and $\mathrm{NaOH}$ along with a colourless compound $\left(\mathrm{S}\right)$. $\left(\mathrm{P}\right)$ neither reduce Tollen’s reagent or Fehling’s solution nor it decolourises bromine water. On drastic oxidation of $\left(\mathrm{P}\right)$ with chromic acid, a carboxylic acid $\left(\mathrm{T}\right)$ having molecular formula ${\mathrm{C}}_7{\mathrm{H}}_6{\mathrm{O}}_2$ is obtained. Deduce the structures of the compounds $\left(\mathrm{P}\right)$ to $\left(\mathrm{T}\right)$.