A mechanistically designed bis-cinchona alkaloid ligand allows position- and enantioselective dihydroxylation of farnesol and other oligoprenyl derivatives at the terminal isopropylidene unit

Abstract

The mechanistically designed bis-cinchona alkaloid derivative 3 serves as an excellent catalytic ligand in the OsO4-promoted catalytic enantioselective dihydroxylation of the terminal isopropylidene group infamesyl, geranylgeranyl, and solanesyl esters and also squalene, with selectivity as high as 120: 1 with E,E-farnesyl acetate. 1H NMR and X-ray studies support the conformation described by 3 in which the V-shaped catalytic binding pocket is composed of the two 6-(4-heptyloxy)-quinoline units (sides and rear) and the naphthopyridazine linker (bottom). © 1995, All rights reserved.