Aluminium Oxide Assisted Stereoselective Rearrangement of a Cyclopropyl Ketone to 4,5-Dihydrofuran
Contrary to the general observation that thermally and photochemically induced cyclopropyl ketone to dihydrofuran arrangements take place with partial loss of the stereochemical identity of the starting cyclopropane, a characteristic shared by the closely related vinylcyclopropanes and vinyloxiranes, a case of totally stereospecific, alumina-assisted cyclopropyl ketone to dihydrofuran rearrangement at room temperature was observed.