Isoprene is the repeating unit in natural rubber. The structure of isoprene is a. Give a systematic name for isoprene. b. When isoprene is polymerized, two polymers of the form are possible. In natural rubber, the cis configuration is found. The polymer with the trans configuration about the double bond is called gutta percha and was once used in the manufacture of golf balls. Draw the structure of natural rubber and gutta percha showing three repeating units and the configuration about the carbon-carbon double bonds.

Isoprene has the following chemical structure: CH2=C(CH3)CH=CH2

To assign a systematic name to isoprene, we can use the IUPAC nomenclature. In this case, the molecule has a total of 5 carbon atoms, making it a pentene molecule (with a double bond). The methyl (CH3) group is in the 2nd position, and the first double bond is in the 1st position, so the systematic name for isoprene would be: 2-Methyl-1,3-butadiene

When isoprene is polymerized, it forms two different polymers with cis or trans configurations around the carbon-carbon double bond. Natural rubber has a cis configuration. To draw the structure of natural rubber, we must show the cis arrangement around carbon-carbon double bonds. We can draw three repeating isoprene units in the following way: \( CH_2=C(CH_3)CH=CH_2-CH_2=C(CH_3)CH=CH_2-CH_2=C(CH_3)CH=CH_2 \) Gutta percha has a trans configuration. To draw the structure of gutta percha, we must show the trans arrangement around carbon-carbon double bonds. We can draw three repeating isoprene units in the following way: \( CH_2=C(CH_3)-CH=CH_2-CH_2=C(CH_3)-CH=CH_2-CH_2=C(CH_3)-CH=CH_2 \) Where each repeating -CH2=C(CH3)-CH=CH2- unit represents the polymerized isoprene unit in their respective cis or trans configurations.