Photochemical reactions. 137th communication. Preparation and photolysis of (E/Z)-7-methyl-?-ionone
作者:Keitaro Ishii、Peter Mathies、Takehiko Nishio、Hans Richard Wolf、Bruno Frei、Oskar Jeger
DOI:10.1002/hlca.19840670502
日期:1984.8.8
The title compounds (E/Z)-7 were prepared in 66% overall yield by reaction of β-ionone ((E)-(1) with lithium dimethylcuprate, trapping of the intermediate enolate with benzeneselenenyl bromide and oxidation with H2O2. Analogously, (E/Z)-7-methyl-α-inone ((E/Z)-12) was obtained in 65% yield from α-ionone ((E)-11). 1n, π*- Excitation (λ > 347 nm, pentane) of (E)-7 causes rapid (E/Z)-isomerization and subsequent
通过β-紫罗兰酮((E)-(1)与二甲基铜锂的反应,中间体烯醇盐与苯硒烯基溴化物的俘获并与H 2 O 2的氧化,以66%的总收率制备标题化合物(E / Z)-7类似地,从α-紫罗兰酮((E)-11)以65%的收率获得(E / Z)-7-甲基-α-茚酮((E / Z)-12)1 n,π * -激发(E)-7的(λ> 347 nm,戊烷)引起快速(E / Z)异构化和随后的(Z)-7至15(66%)。形成15是由二烯酮生色的加捻由于7-CH的排斥相互作用解释3 -基团与CH 3级己烯环的-基团。另一方面,在酸存在下照射(E)-7的λ> 347nm,Et 2 O)导致(Z)-7(5%)和新化合物16(88%)。