The molecule is one of three isomeric monoterpenes differing in the positions of their two double bonds (alpha- and gamma-terpinene being the others). In beta-terpinene the double bonds are at the 1(7)- and 3-positions of the p-menthane skeleton. beta-Terpinene has no known natural source.
4-methylidene-1-propan-2-ylcyclohexene