Nature Chemistry 5, 428–432 (2013); published online 7 April 2013; corrected after print 26 April 2013 and 2 May 2013.

In the version of this Article originally published, references to certain compound numbers in the Methods section were incorrect: Under the heading 'General experimental' “...conversion of 3 into n-nonane...” should have read “...conversion of 2 into n-nonane...”. In 'Conversion of A into 2,5,8-nonanetrione 4', “... solvent removed in vacuo to yield 3...” should have read “... solvent removed in vacuo to yield 4...”. In 'Conversion of B into 2,5,8-nonanetrione 4', “... solvent removed in vacuo to yield 3...” should have read “... solvent removed in vacuo to yield 4...”. These errors have been corrected in the HTML and PDF versions of the Article.