NMR determination of the absolute configuration of an alpha-exo-methylene-gamma-lactone.
Both the enantiomers of the axially chiral reagent, 2'-methoxy-1,1'-binaphthalene-2-carbohydroximoyl chloride (MBCC), were used to convert igalan, an alpha-exo-methylene-gamma-lactone, to yield 4,5-dihydroisoxazoles. The absolute configuration of igalan was determined to be (3aR,5R,6R,7aR)-6-ethenylhexahydro-6-methyl-3-methylen e-5-(1-methylethenyl)-2(3H)-benzofuranone (IUPAC name) on the basis of NOE correlations in these derivatives. The absolute configurations of other alpha-exo-methylene-gamma-lactones can be determined by the same method.
Fukui
H
H
Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
Fukushi
Y
Y
Tahara
S
S
D007783:Lactones / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008968:Molecular Conformation
D007783:Lactones; C416683:methylene-lactone