Spacer-mediated synthesis of contra-thermodynamic spiroacetals: Steroselective synthesis of C2-symmetric difructose dianhydrides

The xylylene moiety is employed as a rigid tether in the spacer-mediated synthesis of difructose dianhydrides (DFAs), a unique class of bis-spiroacetal derivatives present in food products. The rigid spacer concept is implemented to favor intermolecular processes leading to higher macrocyclic architectures that incorporate the bis-spiro fructodisaccharide subunit.