Stereochemical aspects of synthetic and naturally occurring 2-hydroxy fatty acids

摘要: Abstract d - and l -Cerebronic acid 5 , 6 methyl esters were obtained from a dl -mixture by converting the racemic ester to -acetylmandelates separating diastereomers thin-layer chromatography; diasteromers then decomposed with mild methanolysis. The optical purities of -enantiomers determined as described below found be 82.5% 87.1%, respectively. Absolute configurations enantiomers confirmed their ORD spectra; specific rotations at peak anomalous curves 223 nm -isomers −989 ° +1120 °, Considering purities, actual maximum these calculated −1520 +1509 conditions for reaction -acetylmandelyl chloride 2-hydroxy fatty modified suitable assay esters. method was also shown applicable 3-hydroxy isomers possibly other positional isomers. absolute configuration calf brain cerebrosides yeast cerebrins (−), confirming previous assignments. Methyl cerebronate its less soluble strychnine salt (+)-enantiomer, contrary assignment. -cerebronate hydrolyzed tetrahydrofuran-HCl obtain D-cerebronic without racemization.