Photochemistry of the anthracene chromophore: Synthesis and photochemical isomerization of 1,2-di(9-anthryl)-1-hydroxypropene, a novel simple enol
✍ Scribed by Hans-Dieter Becker; Kjell Andersson
- Publisher
- Elsevier Science
- Year
- 1987
- Tongue
- French
- Weight
- 242 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
Enolization and subsequent methylation of 1,2-di(9-anthryllethanone leads to photolabile E/Z-isomeric a,&substituted dianthrylethylenes. 1,2-Di(9-anthryljpropanone forms a crystalline enol which isomerizes photochemically in solution by a unique H shift. Isolable simple enols typically are stabilized by bulky aryl groups such as mesityl, and they are usually prepared by the method of Fuson which involves the addition of an aryl Grignard reagent to a diary1 substituted ketene. 1,2 The potential formation of E/Z isomers is commonly circumvented by employing symmetrically substituted ketenes, as e. g. in the synthesis of 1-(9-anthryl)-Z,Z-dimesitylethenol from 9-anthrylmagnesium bromide and dimesitylketene. 3 Recent interest in simple enols has been focussed on their photochemical rearrangement, 4 and on the steric effects on the enol/ketone equilibrium.