Synthesis and stereochemistry of some bicyclic gamma-lactones from parasitic wasps (Hymenoptera: Braconidae). Utility of hydrolytic kinetic resolution of epoxides and palladium(II)-catalyzed hydroxycyclization-carbonylation-lactonization of ene-diols.
A palladium(II)-catalyzed hydroxycyclization-carbonylation-lactonization sequence with appropriate pent-4-ene-1,3-diols provides efficient access to the bicyclic gamma-lactones, 5-n-butyl- and 5-n-hexyltetrahydrofuro-[3,2-b]furan-2(3H)-ones (3) and (4), respectively, in both racemic and enantiomeric forms. Some of the substrate pent-4-ene-1,3-diols of high enantiomeric excess (ee) have been derived from racemic terminal epoxides by hydrolytic kinetic resolution (HKR) using cobalt (III)-salen complexes. (9Z,12R)-(+)-Ricinoleic acid also serves as a "chiral pool" source of other pent-4-ene-1,3-diols. These syntheses and enantioselective gas chromatography confirm the structures and absolute stereochemistry of the lactones in some species of parasitic wasps (Hymenoptera: Braconidae). The highly abundant 5-n-hexyltetrahydrofuro-[3,2-b]furan-2(3H)-one (4) in Diachasmimorpha kraussii and D. longicaudata is of high ee (>99%) with (3aR,5R,6aR) stereochemistry.
Paddon-Jones
G C
GC
Department of Chemistry, The University of Queensland, Brisbane, Q. 4072, Australia.
McErlean
C S
CS
Hayes
P
P
Moore
C J
CJ
Konig
W A
WA
Kitching
W
W
D000818:Animals; D001685:Biological Factors / Q000138:chemical synthesis; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis*; D004330:Drosophila; D007306:Insecticides / Q000138:chemical synthesis; D007783:Lactones / Q000138:chemical synthesis*; D010271:Parasites / Q000737:chemistry; D013237:Stereoisomerism; D014863:Wasps / Q000737:chemistry*
D001685:Biological Factors; D019086:Bridged Bicyclo Compounds, Heterocyclic; D007306:Insecticides; D007783:Lactones