- Preparation and Catalytic Hydrogenation of Spiro and Sprio
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Wittig monoolefination of acenaphthylene-1,2-quinone (1) with ethyl (triphenylphosphoranylidene)acetate yields the o-quinomethane derivative 2 which by 1,3-dipolar cycloaddition reactions with aromatic nitrile oxides affords regioselectively the spiro 3 and 4.Reaction between 1 and benzonitrile oxide gives the spiro 5 which by treatment with ethyl(triphenylphosphoranylidene)acetate gives compound 6.Reaction between 6 and benzonitrile oxide gives regioselectively the diastereomeric dispiro compounds 7 and 7'.Catalytic hydrogenation of the spiro compounds 6,7, and 7' over 10percent Pd/C results in the cleavage of the dioxazole ring while cleavage of the isoxazole ring of compound 3 is achieved either by reduction over Raney nickel or by treatment with sodium ethoxide.Reduction of products prepared according Scheme 1 affords the acenaphthylene derivatives 8,9 and 12-15.
- Lefkaditis, Demetrios A.,Argyropoulos, Nicolaos G.,Nicolaides, Demetrios N.
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p. 1863 - 1871
(2007/10/02)
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