Chemistry of Diazoacenaphthenones and Diazoacenaphthenes

Article abstract of DOI:10.1021/jo00143a010

Wolff rearrangements do not occur in photolyses or thermolyses of diazoacenaphthenone (1), 2-diazo-5-nitroacenaphthenone (2), and 2-diazoaceanthrenone (3) in various environments.Thermal and photochemical decompositions of 1 in cyclooctane result in loss of nitrogen and formation of 2-cyclooctylacenaphthenone (29).In 2-propanol containing oxygen, 1 converts photolytically to acenaphthenone (22), acetone (23), and 1,8-naphthalic anhydride (25).Irradiation of 1 in tert-butyl alcohol/oxygen yields 2-tert-butoxyacenaphthenone (28) by solvent capture along with 25.Diazoketones 1-3 do not effect photochemical cyclopropanation of simple olefins; electronegatively substituted olefins such as acrylonitrile and methyl acrylate do give spirocyclopropanes however.Oxazoles are formed by 1,3-dipolar reactions of 1-3 with nitriles with loss of nitrogen.Acetylenes also react photolytically with 1-3 with nitrogen expulsion to yield furanes regiospecifically.Thermolyses of 1-3 in acetylenes, however, result in initial 1,3-dipolar addition reactions to give spiropyrazoles which undergo spotaneous <1,5> sigmatropic migrations of their carbonyl groups to nitrogen to form isoquinolines.Diazoacenaphthene (13) decomposes carbenically to acenaphthylene (66).Similarly, 2-diazo-1,1-dimethylacenaphthene (14) converts to 8-methylcyclopropacenaphthylene (66) which then isomerizes thermally to methylphenalenes (70a-d).Further, 2-diazoacenaphthenone ethylene acetal (17) thermolyzes and photolyzes with migration of one of its acetal oxygen moieties to yield 8,9-dihydroacenaphtho<1,2-b>-p-dioxin (73).Ring contraction does not occur in carbenic decompositions of 13, 14, and 17.