ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Vinylogous β-Cleavage of Epoxy-enones: Photoisomerization of 3,4: 5,6-Diepoxy-5,6-dihydro-β-iononeOn 1n,π*-excitation (λ〉347 nm), 3,4:5,6-diepoxy-5,6-dihydro-β-ionone ((E)-3) shows the typical behaviour of α,β-unsaturated γ,δ-epoxy ketones furnishing the (Z)-enone 3 and by C(γ),O cleavage of the oxirane the dihydrofuryl ketone 10 and the cyclohexanones (E/Z)-11. However, on 1π,π*-excitation an unexpected type of transformation is observed: (E)-3 is isomerized to the four aliphatic triketones 5-8 as the main products. To a smaller extent the allene diketone 9 is formed by a known type of isomerization as well as (Z)-3.As the starting material for the preparation of (E)-3, the known epidioxy-enone (E)-4 was used. In addition to (E)-3, (E)-4 gives the aliphatic triketone 6 and the hydroxyenone 15 by thermal or catalytic isomerization.
Additional Material:
2 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19810640606
Permalink