Hexacyclinol Report Retracted

More than six years after its publication, James J. La Clair’s controversial paper on the total syntheses of hexacyclinol and related compounds has been retracted (Angew. Chem. Int. Ed., DOI: 10.1002/anie.201206869). The retraction was agreed upon by La Clair, Angewandte Chemie Editor-in-Chief Peter Gölitz, and publisher Wiley-VCH Verlag GmbH & Co.

Insufficient supporting information was cited as the cause for the report’s removal, according to a statement on the journal’s website. “In particular, the lack of experimental procedures and characterization data for the synthetic intermediates as well as copies of salient NMR spectra prevents validation of the synthetic claims,” the statement reads.

The total synthesis, of a structure proposed by the late natural products chemist Udo Gräfe, raised eyebrows in the chemical community shortly after its publication in February 2006. Chemists found it odd that La Clair, of San Diego-based Xenobe Research Institute, was the sole author on the seemingly herculean 30-plus-step synthesis, and spectral and experiment data seemed off as well.

The work was further called into question later that year when Scott D. Rychnovsky, a natural products chemist at the University of California, Irvine, proposed a revised structure for hexacyclinol—one that was quite different from what La Clair purportedly synthesized. When a group led by Boston University’s John A. Porco Jr.synthesized the revised structure of hexacyclinol and found it spectroscopically identical to the compound isolated by Gräfe, considerable doubt was cast upon La Clair’s report and calls for its retraction grew louder.

“This paper was retracted based on the fact that it lacked sufficient spectral data supporting the synthetic intermediates as well as detailed 2-D NMR analyses on the isolated and synthetic final products, an omission that fueled considerable controversy,” says La Clair about the retraction. Neither he nor the journal elaborated on the time it took to retract the work.

“I was pleased to see the retraction,” Rychnovsky comments. “It is helpful to clean up this discrepancy in the literature.”