ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The Thermal, Catalytic, and Photochemical Denitrogenation of 1-Diazo-3-(1-methylcyclopenta-2,4-dienyl)-2-propanoneThe synthesis of the title compound 12 is described. This diazoketone, distinguished by its Cs-symmetry and by a built-in cisoid diene unit, gives 5-methyltricyclo[3.3.0.02,8]oct-6-ene-3-one (13) when subjected to thermal or catalytic denitrogenation with rhodium (II) acetate or copper (II) acetylacetonate. Direct irradiation of 12 at 350 nm causes Wolff rearrangement, whereas the benzophenone-sensitized photolysis gives again ketone 13. A 1,4-carbene or carbenoid addition was never observed under the conditions described. The ketone 13 equilibrates thermally or under base catalysis with 1-methyltricyclo[3.3.0.02,8]oct-6-ene-3-one (17). The key step of this apparent CH3 migration is shown to be a Cope rearrangement of the corresponding enols (hydroxysemibullvalenes).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19860690318
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