UV-induced isomerisation and ring transformation of (E)-3-arylidene-1-thiochromanones and -1-thioflavanones
Abstract
Depending on the substituent of the arylidene moiety, photoisomerisation of (E)-3-arylidence-1-thiochroman-4-ones 1 and 3 afforded either the expected (Z)-1 and (Z)-3 isomers or the products (2d,e and 4c,d) of an unprecedented phototransformation.