Cycloaddition Done By Diols

Chemists have used cycloaddition reactions to construct cyclic compounds for more than a century. Now vicinal diols, molecules with OH groups on neighboring carbon atoms as in the commonplace compound glycerol and the natural polymer cellulose, can be added to the list of reagents that undergo cycloadditions. Michael J. Krische and colleagues at the University of Texas, Austin, report redox-triggered couplings of dienes with diols, which yield [4 + 2] cycloaddition products, shown (J. Am. Chem. Soc., DOI: 10.1021/ja400691t). A ruthenium(0) catalyst enables successive C–C coupling of dienes with vicinal diols. Both cyclic and acyclic vicinal diols participate in the cycloaddition, which yields single-diastereomer products. Furthermore, the reaction works on the diols’ more highly oxidized forms—hydroxyketones and diones—to give identical diol cycloadducts. The reaction “opens up new routes for the conversion of glycerol and other glycols to commodity chemicals,” Krische says.