Revised Absolute Configurations of Latifolic Acid and the Pyrrolizidine Alkaloid Latifoline

Abstract

The absolute stereochemistry of (+)- latifolk acid has been determined by single-crystal X-ray crystallographic analysis to be (2S,3R,4R)-3- hydroxy-2,4-dimethyl-5-oxotetrahydrofuran-3-carboxylic acid. The configuration of the three chiral centres is opposite to that presently recorded in the literature. Accordingly, the configuration of the pyrrolizidine alkaloid, latifoline, which includes a latifolic acid side chain, must be revised.