Alpha terpene, C10H16, is a pleasant-smelling hydrocarbon that has been isolated from oil of marjoram. On hydrogenation over a palladium catalyst, alpha terpene reacts with two molar equivalents of H2 to yield a hydrocarbon C10H20. On ozonolysis, followed by reduction with zinc and acetic acid, alpha terpene yields two products, glyoxal and 6-methyl-2,5-heptanedione.

a. How many degrees of unsaturation does alpha terpene have?

b. How many rings and double bonds does it have?

c. Propose a structure for alpha terpene