Synthetic rubber was first produced in the 1920's - and was achieved by the polymerisation of butadiene (obtained from petroleum), which is structurally similar to isoprene, less the methyl group:

In 1955, chemists at the Goodyear and Firestone tyre companies discovered how to use catalysts to prepare synthetic poly-cis-isoprene - which is structurally identical to natural rubber. The process is used today, as an alternative to the harvesting of natural rubber - which is still cheaper to produce, but not an environmentally sound idea.