Photoreaction of a stable thioaldehyde 2,4,6-tri-tert-butylthiobenzaldehyde
Abstract
The photochemical reaction of the only isolable aromatic thioaldehyde ArCHS (1; Ar = 2,4,6-tri-tert-butylphenyl) in alkaline medium yields ArCH2CH2Ar (2), ArCH2SCH2Ar (3), 6,8-di-tert-butyl-3,4-dihydro-4,4-dimethyl-1H-2-benzothiine (4) and ArMe (5). A radical mechanism which accounts for the formation of these compounds is proposed, mainly on the basis of the direct observation (EPR spectroscopy) of a number of radicals such as ArCHS˙–(A), ArCHCH2Ar (B), and ArCH2˙(D). Results of scrambling of deuterium atoms confirmed the structure of these radicals through interpretation of the corresponding EPR spectra.