Propane can be best prepared by the reaction

${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{Na}\underset{630\mathrm{K}}{\overset{\mathrm{NaOH}/\mathrm{CaO}}{\to }}$

${\mathrm{CH}}_3\mathrm{COONa}+{\mathrm{CH}}_3\mathrm{COONa}\underset{\mathrm{Electrolysis}}{\overset{{\mathrm{H}}_2\mathrm{O}}{\to }}$

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{I}+{\mathrm{CH}}_3\mathrm{I}\underset{\mathrm{\Delta }}{\overset{\mathrm{Nalether}}{\to }}$

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{Br}+{\left({\mathrm{CH}}_3\right)}_2\mathrm{CuLi}\underset{\mathrm{\Delta }}{\overset{\mathrm{ether}}{\to }}$