ABSTRACT
It is now well established, based largely on early studies by Yates and Turro, that irradiation of cyclobutanones leads to the formation of an oxacarbene as one of the preferred reaction pathways (Scheme 1).
The highly reactive oxacarbene can be intercepted by trapping with water or an alcohol to give a lactol or an acetal, respectively (Scheme 1). The same reaction manifold is followed by some cyclopentanones, especially when the five-membered ring is part of a strained structure (Scheme 2).
