New synthetic methodology for 3-aminotropones

A new synthetic methodology for 3-aminotropones is described. Tropones and 3-aminotroponic building blocks, present in a number of active natural products, could be prepared by a two step synthetic pathway: a first step consisting in a [4+3] cycloaddition reaction between a conveniently substituted α,α′-dihaloketone and a furan derivative functionalized on C-2 by a protected amino group. The second step is based on a rearrangement of the cycloadduct, via the cleavage of the oxygen bridge, under basic conditions.