Synthesis and Photochemical Properties of 1,3-Di-9-anthryl-2-propanol, 1,3-Di-9-anthrylacetone, and Related Propano-Linked Anthracenes

Article abstract of DOI:10.1021/jo00274a040

9-Anthryllithium reacts with epichlorohydrin to give 1,3-di-9-anthryl-2-propanol via 3-(9-anthryl)-1-chloro-2-hydroxypropane and 3-(9-anthryl)-1,2-epoxypropane.Oxidation of dianthryl-2-propanol with Dess-Martin reagent gave 1,3-di-9-anthrylacetone.Various other 1,3-bichromophoric anthracenes were synthesized by way of C-methylation of dianthrylacetone, 1,3-di-9-anthryl-1-propanone, and 1,3-di-9-anthrylpropenone. 9-Anthrylacetone, formed as byproduct in the reaction of anthryllithium with epichlorohydrin, was prepared from 9-anthrylacetaldehyde by Grignard reaction with methylmagnesium iodide and subsequent oxidation.The excited-state properties of dianthryl-2-propanol, dianthrylacetone, 1,3-di-9-anthryl-2-methyl-1-propanone, 1,3-di-9-anthryl-2-methyl-2-propanol, diastereomeric 1,3-di-9-anthryl-1-butanols, 1,3-di-9-anthryl-2-butanone, 1,3-di-9-anthryl-1-butanone, and diastereomeric 1,3-di-9-anthryl-2-methyl-1-butanones have been evaluated by fluorescence quantum yields, and by quantum yields for the isomerization by intramolecular 4? + 4? cycloaddition.Dianthryl-2-propanol, 1,3-di-9-anthryl-2-methyl-2-propanol, dianthrylacetone, diastereomeric 1,3-di-9-anthryl-1-butanols, and 1,3-di-9-anthryl-2-butanone isomerize in their excited singlet state with quantum yields of 0.046, 0.021, 0.25, 0.23, and 0.22, respectively.The photochemical isomerization of those 1,3-bichromophoric anthracenes which are characterized by a 9-anthroyl chromophore involves the excited triplet state, and the cyclization quantum yield may be as high as 0.72.