54344-73-9Relevant articles and documents
Copper-Catalyzed Conjugate Addition of Trialkylaluminium to α,β-Unsaturated Carbonyl Compounds
Kabbara, Jazid,Flemming, Steffen,Nickisch, Klaus,Neh, Harribert,Westermann, Juergen
, p. 743 - 754 (2007/10/02)
The Michael-type reaction of copper-catalyzed trialkylaluminium reagents with α,β-unsaturated carbonyl compounds is a useful and simple procedure for the transfer of hydrocarbon substituents.The scope of this process and the effect of chlorotrimethylsilane as additive were investigated.Preparatively useful results were generally obtainde from enones even with higher organoaluminium reagents, whereas the reaction with α,β-unsaturated aldehydes was limited to the use of trimethylaluminium.
Photochemical Reactions. 137-th Communication. Preparation and Photolysis of (E/Z)-7-Methyl-β-ionone
Ishii, Keitaro,Mathies, Peter,Nishio, Takehiko,Wolf, Hans Richard,Frei, Bruno,Jeger, Oskar
, p. 1175 - 1183 (2007/10/02)
The title compounds (E/Z)-7 were prepared in 66percent overall yield by reaction of β-ionone ((E)-1) with lithium dimethylcuprate, trapping of the intermediate enolate with benzeneselenyl bromide and oxidation with H2O2.Analogously, (E/Z)-7-methyl-α-ionone ((E/Z)-12) was obtained in 65percent yield from α-ionone ((E)-11). 1n,?*-Excitation (λ > 347 nm, pentane) of (E)-7 causes rapid (E/Z)-isomerization and subsequent reaction of (Z)-7 to 15 (66percent).The formation of 15 is explained by twisting of the dienone chromofore due to repulsive interaction of the 7-CH3-group with the CH3-groups of the cyclohexene ring.On the other hand, irradiation, (λ > 347 nm, Et2O) of (E)-7 in the presence of acid leads to (Z)-7 (5percent) and to the novel compound 16 (88percent).
