Stereochemistry of the verbenols

Abstract

Nuclear magnetic resonance and chemical evidence shows that the product of lithium aluminium hydride reduction of verbenone is cis-verbenol, and that of lead tetra-acetate oxidation of a-pinene is trans-verbenol. The physical properties of both alcohols differ from those reported for the alcohols separated from the product of Meerwein-Po n ndorf-Verley reduction of verbeno ne.

Insect Pheromones: A Critical Review of Recent Advances in Their Chemistry, Biology, and Application

“…In this case the optical rotation of the cis-verbenol was measured in methanol. Earlier syntheses (51,52) of cis-verbenol from ( -)-verbenone gave a product that was levorotatory in chloroform (52) and dextrorotatory in acetone (51). Both of these results are correct and both groups had in fact obtained (lS,4S,5S)-cis-verbenol (234).…”

Unusual α-hydroxyaldehyde with a cyclopentane framework from verbenol epoxide

“…The optical purity of verbenone {[a] 20 580 -179.5 (c 21.5, CHCl 3 )} 9 employed for the synthesis of (-)-cis-verbenol epoxide 1 is ~60% {lit., 10 [a] 22 D -264 (c 3, CHCl 3 ) for verbenone with 90% optical purity}. We determined the optical purity of compound 4 by recording its 1 H NMR spectrum with the chiral shift reagent Eu(hfc) 3 .…”

Synthesis of Optically Pure (1S, 4S, 5S)-2-Pinen-4-ol (cis-Verbenol) and Its Antipode, the Pheromone ofIpsBark Beetles

“…To our surprise, in these two solvents our (+ )-cis-verbenol (4a) was levorotatory, [am 12.8° (methanol) and -6.8° (acetone), while the ( )-enantiomer (4a') was dextrorotatory, [aW+ 11.4° (methanol) and +6.2° (acetone). Thus it became clear that both Silverstein 5 I and Whittaker 6 ) correctly obtained (I S, 4S, 5S)-cis-verbenol (4a') from ( )-verbenone (3'). The inconsistency was due to the use of different solvents for their rotation measurements.…”