Some free-radical addition reactions of pin-2-ene, pin-2(10)-ene, and thuj-4(10)-ene

Abstract

The addition of free-radical reagents, other than thiols, to pin-2(10)-ene leads to the formation of ring-opened products. In the addition of thiols, products of 1,2-addition to the double bond are formed. The addition of carbon tetrachloride to pin-2-ene affords products of ring opening, but the addition of thiols affords the products of 1,2-addition to the double bond. The addition of bromotrichloromethane to pin-2-ene is complex and as well as the ring-opened product it is likely that products of allylic bromination, and products having limonene and bicyclo[2,2,1]heptane type structures are also formed. In the addition both of carbon tetrachloride and of thiols to thuj-4(10)-ene, products of ring opening alone are formed. The rate of chain transfer with the first-formed intermediate radical probably decides whether or not products of ring opening are formed in the free-radical addition reactions of the terpenes mentioned.