Paterno‐Büchi Reaction

AbstractThis reaction is a photo‐induced [2 + 2] cycloaddition of carbonyl compounds with olefins or other unsaturated substrates to form four‐membered cyclic ethers, known as oxetanes, with high regio‐ and stereoselectivity and is known as the Paterno–Büchi reaction. This reaction is often sluggish and also competes with the radical polymerization of alkenes. The regioselectivity of major oxetane from asymmetric olefins follows the Markovnikov rule through the formation of the most stable biradical intermediates. However, the stereoselectivity is controlled by the nature of reaction pair, temperature, and hydrogen bonding. The Paterno–Büchi reaction is very useful process in organic synthesis.