ISSN:
0947-3440
Keywords:
[2.2]Paracyclophane, hydrogenation of
;
Olefins, strained
;
Dichlorocyclopropanation
;
Dichlorocyclopropanes
;
Polycycles
;
Cyclophanes
;
Cage compounds
;
Strained molecules
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The catalytic hydrogenation of [2.2]paracyclophane 1 has been reinvestigated with the following results: a) Best yields (95%) of the perhydrocyclophane 3 are obtained when 1 is hydrogenated over ruthenium on charcoal in ethanol at 200°C and 300 atm in the presence of lithium hydroxide; b) hydrogenation of 1 in ethyl acetate/acetic acid over platinum at room temperature and normal pressure leads to the monoene 7 and one diene, to which we assign structure 11 since dichlorocyclopropanation converts it to the bis-adduct 12, whose structure was determined by X-ray structural analysis; c) when the tetraene 13 (prepared from 1 by Birch reduction) is hydrogenated over palladium on charcoal in petroleum ether, the triene 14 is obtained in addition to the dienes 4 and 11. Again, dichlorocyclopropanation followed by X-ray structural analysis of the resulting tris-adduct 17 was employed for the structure determination of the hydrocarbon precursor. The strain energies of the anti-Bredt hydrocarbons 11 and 17 have been calculated by molecular mechanics calculations.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199719970728
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