Anomalous acid-catalyzed reactions of cyclobutanones

Abstract

The reactions of 2(2-isopropanol)cyclobutanones with phosphorous pentoxide lead to ring opened carboxylic acids. Reaction of 2-isopropylidenecyclobutanones with polyphosphoric acid (PPA) gives ring cleavage rearrangement products. The mechanisms of these reactions are discussed in the light of the observed different reactions of the corresponding cyclopentanones.

Acid-catalyzed reactions of cyclobutanones. III. Formation of substituted 2-tetralones from α-phenylcyclobutanones

“…The reactive nature of cyclobutanones with the extensive variation of ring-opening reactions (1)(2)(3) has placed these compounds in a class of synthetically important intermediates. With the recent additions of new routes to such systems, cyclobutanone derivatives become accessible synthons to a host of key functional groups required in alkylation reactions (4).…”