No abstract

A novel low-generation amide dendrimer bearing four ester groups as terminal branches was conveniently synthesised by three-step reactions including acylation, hydrolysis and condensation from benzoyl chloride. Crystal X-ray diffraction and NMR analysis confirmed that one ester group of the four branches with pseudosymmetry was shielded by a benzene ring while the others were much further away. This was a difference from conventional dendrimers with symmetric branch distribution.

The Claisen reaction of arylacetic acids (I) with esters (II) is accompanied by a spontaneous decarboxylation to afford ketones (III).