84368-72-9Relevant articles and documents
Photoreactions of γ,δ-unsaturated chromium carbene complexes
Moser, William H.,Hegedus, Louis S.
, p. 7873 - 7880 (2007/10/03)
A number of functionalized γ,δ-unsaturated chromium carbene complexes were synthesized, and their photochemistry was studied. Photolysis of carbene complexes 5 and 17 induced intramolecular [2 + 2] cycloaddition to afford cyclobutanones 6 and 18, respectively. If the photoreactions were not run in thoroughly degassed solvents, small amounts of lactones 7 and 19 were obtained as well. Cyclobutanones 6 and 18 were stable once isolated, but underwent an acid-catalyzed Pinacol rearrangement/hydrolysis transformation in acidic solution to afford novel α-hydroxy-substituted bicyclo[3.1.0]hexanone compounds 20 and 21. Photolysis of cyclopropyl carbene complex 28 induced a vinylcyclopropyl rearrangement involving the photogenerated ketene moiety to provide α-alkoxy cyclopentenone 29.