Synthesis of fumaramide derived [3]rotaxanes as potential precursors for molecular boxes.

Three new fumaramide-derived [3]rotaxanes have been synthesized, with the aim of macrocycle linking to form a molecular box. In one case, a nine-component templated [3]rotaxane synthesis was accomplished in 40% yield. Rotaxane reduction resulted in an unexpectedly facile de-slipping process.

Aromatic compounds as synthons for 1,3-dicarbonyl derivatives.

This tutorial review covers the applications of aromatic compounds such as anisole derivatives as synthetic equivalents (synthons) for 1,3-dicarbonyl compounds. The aromatic nucleus is first converted under reductive Birch conditions to the corresponding 1,4-cyclohexadiene compound which is then subjected to ozonolysis. The reductive work-up of the ozonides generates the 1,3-dicarbonyl compounds. The usefulness of this reaction sequence is demonstrated in several syntheses of complex molecules. A new access to 1,3-dicarbonyl compounds by an alternative approach utilising a cobalt-catalysed Diels-Alder reaction or a 1,4-hydrovinylation reaction to generate the needed 1,4-diene derivatives is briefly discussed.