13C NMR-based empirical rules to determine the configuration of fatty acid butanolides. Novel gamma-dilactones from Pterogorgia spp.
Diastereomeric gamma-dilactones isolated from Pterogorgia spp allowed the establishment of (13)C NMR-based empirical rules to determine the relative stereochemistry of 3-alkyl-4-hydroxy-5-methyl-2(5H)-dihydrofuranones, gamma-lactone moieties ubiquitous in many bioactive synthetic and natural products. An NMR-based method using Pirkle's reagent at low temperature allowed the absolute configuration of the naturally occurring dibutenolides to be unambiguously determined. A biogenetic pathway that involves oxidation of long-chain (C16:0 and C18:0) fatty acids is proposed. [structure: see text]
Lorenzo
Manuel
M
Instituto de Productos Naturales y Agrobiología del CSIC, Avenida Astrofísico F. Sanchez 3, 38206 La Laguna, Tenerife, Spain.
Brito
Inmaculada
I
Cueto
Mercedes
M
D'Croz
Luis
L
Darias
José
J
D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000737:chemistry; D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D005227:Fatty Acids / Q000737:chemistry; D007783:Lactones / Q000737:chemistry* / Q000302:isolation & purification*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D013237:Stereoisomerism
D005227:Fatty Acids; D007783:Lactones; D015107:4-Butyrolactone