Palladium catalyzed oxidation of monoterpenes: novel oxidation of myrcene with dioxygen

Abstract

Myrcene can be efficiently and selectively oxidized by dioxygen in glacial acetic acid containing LiCl, in the presence of the PdCl 2–CuCl 2 catalytic combination, yielding two isomers of a new functionalized monoterpene, i.e., 3-(1-acetoxy-1-methylethyl)-1-vinylcyclopentene and 4-(1-acetoxy-1-methylethyl)-1-vinylcyclopentene, as major products. These compounds have a pleasant scent with a flower or fruit tinge and could be used as components of synthetic perfumes. The activities of Pd(OAc) 2–LiNO 3, Pd(OAc) 2–Cu(NO 3) 2 and Pd(OAc) 2–benzoquinone systems in myrcene oxidation have also been examined.