RESULTS AND DISCUSSION Inspired by the spectroscopic work on iron(III)-salicylic acid complexes in water, we started our investigations with the photoreaction between tetrahydro-4H-pyran-4-on (1) and trifluoromethyl acrylonitrile (2) with a catalytic system of Fe(ClO4)3 H2O (20 mol%), LiCl (20 mol%) and salicylic acid (20 mol%) at 385 nm in de-ionised water under N2 atmosphere. After irradiating the reaction solution for 24 h the purple colour of the mixture faded and 38% of two diastereomers could be observed in F-NMR spectroscopy. Starting material 1 was chosen due to the reactive α-oxygen C-H bond and compound 2 allowed for the F-spectroscopic monitoring of product formation. The results from a reaction condition screening are summarised in Table .