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Azo Bridges from Azines, XX.
Author(s) -
Brand Uwe,
Hünig Siegfried
Publication year - 1996
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.199619960419
Subject(s) - nitrile , chemistry , moiety , triethylamine , cage , bridge (graph theory) , yield (engineering) , strain (injury) , stereochemistry , polymer chemistry , medicinal chemistry , organic chemistry , composite material , structural engineering , materials science , medicine , engineering
of a cyano group into the olefinic bridge of 10 (type A ) leads to the formation of 16 (type C ) in high yield. To obtain 16 first 10 is transformed into isoxazoline 11 which is opened to hydroxy nitrile 12 (type B ) from which after brosylation ( 15 ) 16 is isolated. Reduction of the azo bridge in 15 affords half cage 13 . Smooth oxidation of 12 yields oxo nitrile 19 , from which under basic conditions another half cage ( 18 ) results. Unexpectedly, on heating with triethylamine 19 undergoes complete rearrangement of the bridges, 21 being formed on release of strain. The course of this reaction which has to pass through a cage with a diazetidine moiety is discussed.