Propyne is treated with NaNH2 and then with CH3CH2Br to give A. A is partially hydrogenated with H2 and Lindlar catalyst to give B. B is subjected to ozonolysis followed by Zn/H2O. The products are

ethanoic acid and propanoic acid

JEE Advanced levelSingle correct optionDifficulty 3 of 3si165

Propyne is treated with $NaNH X_{2}$ and then with $CH X_{3} CH X_{2} Br$ to give A. A is partially hydrogenated with $H X_{2}$ and Lindlar catalyst to give B. B is subjected to ozonolysis followed by $Zn / H X_{2} O$ . The products are

The acetylide

CH X_{3} C \equiv C X^{-}

is ethylated to pent-2-yne,

CH X_{3} C \equiv CCH X_{2} CH X_{3}

(A). Lindlar catalyst gives cis-pent-2-ene (B). Reductive ozonolysis cleaves

C = C

into

CH X_{3} CHO

and

CH X_{3} CH X_{2} CHO

. The acids would be formed by oxidative work-up.