The 1,2-addition of one equivalent of HCl to the triple bond of vinylacetylene, HC≡C—CH=CH2, gives a chlorine- containing conjugated diene called chloroprene.

Chloroprene can be polymerized to give neoprene, valued for its resistance to oils, oxidative breakdown, and other deterioration. Give the structures of chloroprene and neoprene. (Assume a 1,4-addition polymerization for purposes of this problem.)