A consecutive ring expansion strategy towards the macrocyclic core of the solomonamide natural products

A synthetic strategy based on the application of three consecutive ring expansion reactions has been used in the synthesis of analogues of the macrocyclic core of the solomonamide natural products. Starting from a simple, readily available tetrahydrocarbazole, oxidative ring expansion is followed by two further 3-and 4-atom ring expansion reactions, enabling the insertion of amino acid-and hydroxyacid-derived linear fragments into 15-17-membered ring-enlarged macrocyclic products.