α-Hydroxycyclobutane rearrangement followed by retroaldol cleavage: a novel and powerful technology for the stereocontrolled construction of carbocyclic systems. An easy access to angularly functionalised trans-fused cycloheptanoids

Abstract Acid-catalysed rearrangement of α-hydroxycyclobutane derivatives 7a–7c and 11a–11c followed by retroaldol cleavage and oxidation in a single operation furnish angularly carboxylated trans-fused cycloheptanoid derivatives 9a–9c and 12a–12c in good yields.