Mechanistic approach to the cyclization reaction of a 2'-hydroxychalcone analogue with light and solvent.

A photochemical cyclization reaction of 1-(2'-hydroxy-1'-naphthyl)-3-(1-naphthyl)-2-propen-1-one (1,1-NHC) to give a flavanone derivative took place in benzene, but did not take place in methanol and the controlling factor of the reaction was discussed based on laser transient spectroscopy and product analysis.