JEE Main · 2023 · 01 Feb 2023 · Shift 1 · Practical and Analytical Chemistry

The compound dissolves in neither alkali nor acid and gives no precipitate with 2,4-dinitrophenylhydrazine, so it has no acidic, basic or carbonyl group and must be an ether. Its formula ${\mathrm{C}}_9{\mathrm{H}}_{10}\mathrm{O}$ carries five degrees of unsaturation, four of them in a benzene ring and one in a carbon-carbon double bond, and hydrogenation of that double bond must furnish a single saturated ether ${\mathrm{C}}_9{\mathrm{H}}_{12}\mathrm{O}$. Both allyl phenyl ether, ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{OC}{\mathrm{H}}_2\mathrm{CH}=\mathrm{C}{\mathrm{H}}_2$, and prop-1-enyl phenyl ether, ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{OCH}=\mathrm{CHC}{\mathrm{H}}_3$, meet every condition and both reduce to the one compound propyl phenyl ether. The number of such isomeric compounds is 2.