CaC2→H2OA→HgSO4, 60oCdil. H2SO4B(final). The compound ‘B’ is the reductive ozonolysis product of
Ethene
Isobutene
2-butene
1-butene
A is CH≡CH; B is CH3CHO CH3-CH=CH-CH3→Zn+H2OO3 2CH3-CHO ;