Paternò–Büchi reaction

The Paternò–Büchi reaction, named after Emanuele Paternò and George Büchi who established its basic utility and form, is a photochemical reaction that forms four-membered oxetane rings from an excited carbonyl and reacting with an alkene.[1] [2] [3]

Here an electronically excited carbonyl group is added to a ground state olefin yielding an oxetane.

With substrates benzaldehyde and 2-methyl-2-butene the reaction product is a mixture of structural isomers:

Another substrate set is benzaldehyde and furan [4]

The alternative strategy for the above reaction is called the Transposed Paternò−Büchi reaction.

The aza-equivalent of the above reactoin is the Aza Paternò−Büchi reaction.