It's pretty standard to find syntheses in a chemistry journal. But a paper published online last week by the international edition of Angewandte Chemie has got the world of organic chemistry humming. It is the second time this year that the journal has published a complete synthesis for a molecule called hexacyclinol — yet each paper claims a different structure for its final product.

Hexacyclinol is extracted from a mushroom and has some medical potential. The first synthesis of the molecule was published in February by chemist James La Clair of the Xenobe Research Institute in San Diego (J. J. La Clair Angew. Chem. Int. Ed. 45, 2769–2773; 2006).

But La Clair's work raised a few eyebrows. For instance, he said his 37-step synthesis made 3.6 grams of hexacyclinol. “I've never heard of a synthesis of that length producing that much material,” says Larry Overman, an organic chemist at the University of California, Irvine. “There was quite a bit — a lot — of scepticism in the community.”

The sceptics included Scott Rychnovsky, also of Irvine. La Clair claimed that the structure of his compound matched a prediction made in 2002. But Rychnovsky worked out that hexacyclinol should resemble another mushroom compound, panepophenanthrin.

Rychnovsky teamed up with John Porco of Boston University, who came up with a new synthesis (J. A. Porco Jr et al. Angew. Chem. Int. Ed. doi:10.1002/anie.200602854; 2006).

The nuclear magnetic resonance (NMR) spectrum for the product matched the 2002 data, suggesting the team had made hexacyclinol. And the crystal structure confirmed their new prediction about its structure.

Which leaves chemists wondering how La Clair got results confirming the original — apparently wrong — structure. And how such a controversial synthesis made it into a peer-reviewed journal. “I can't see any legitimate explanation for the original work,” says Rychnovsky.

La Clair now says that he and Porco may have made two different molecules that happen to have very similar NMR spectra. He has no plans to retract his paper, but has offered to change the name of the compound he says he synthesized.

Because La Clair is unaffiliated with an institution other than the privately funded Xenobe, there is no obvious body to investigate what happened.

Peter Gölitz, editor of Angewandte Chemie, says La Clair's paper was recommended by three well-qualified reviewers. He declined to comment on whether the paper will be retracted. But he says he invited Rychnovsky to publish “so that the discussion and clarification can be done at the place where the original paper was published”.