Q.How will you convert acetone into propane ?

Clemmensen reduction — treating the ketone with zinc amalgam and concentrated hydrochloric acid — reduces acetone's carbonyl group directly to $-CH_2-$, converting it to propane.

Acetone, $CH_3-CO-CH_3$, is a ketone whose carbonyl carbon can be fully reduced to a methylene (-CH$_2$-) carbon using Clemmensen reduction: the ketone is refluxed with zinc amalgam [Zn(Hg)] in the presence of concentrated hydrochloric acid. $CH_3-CO-CH_3 \xrightarrow[\text{conc. }HCl]{Zn(Hg)} CH_3-CH_2-CH_3$ This reaction proceeds under strongly acidic conditions and is used specifically when the rest of the molecule is stable to acid (an alternative, base-mediated method — Wolff-Kishner redu …