Solid-Phase Selenium-Catalyzed Selective Allylic Chlorination of Polyprenoids: Facile Syntheses of Biologically Active Terpenoids

Abstract

Regioselective halogenation of the terminal isopropylidene unit of different acyclic polyolefinic polyprenoids (farnesyl acetate, geranylgeranyl acetate, squalene, etc.) using NCS/catalytic polymer-supported selenenyl bromide is described; good to excellent yields are obtained (68-96%). The first applications of this protocol include the concise synthesis of bioactive terpenoids 1-3.