Rearrangement of α-hydroxycyclobutanes. A facile route towards the carbocyclic skeleton of aplysin via an incipient trichothecane-like cationic intermediate
Abstract
Acid-catalysed rearrangement of cyclobutachromenol (7) followed by oxidation furnishes the tricyclic ketone (9) as the major product, which possesses the carbocyclic framework of aplysin (3).