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Nucleophile Ringöffnung und Fragmentierung von 1‐Aza‐bicyclo[2.2.0]hexan Fragmentierungs‐Reaktionen, 11. Mitteilung
Author(s) -
Grob C. A.,
Krasnobajew V.
Publication year - 1964
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19640470808
Subject(s) - chemistry , bicyclic molecule , piperidine , nucleophile , medicinal chemistry , amine gas treating , reactivity (psychology) , methylene , stereochemistry , organic chemistry , medicine , alternative medicine , pathology , catalysis
1‐Aza‐bicyclo[2.2.0]hexane ( 1 ) is formed in a unimolecular reaction from 2‐(2‐bromoethyl)‐azetidine ( 13 ) in aqueous or alcoholic medium. Thermal instability and high reactivity have, however, so far precluded its isolation. Hydrochloric acid, aqueous sodium hydroxide and ethanolic sodium ethoxide convert the bicyclic amine 1 into 4‐chloro‐, 4‐hydroxy‐ and 4‐ethoxy‐piperidine, ( 14 ), ( 15 ) and ( 16 ), respectively. Upon heating in solution to ca. 80° it undergoes fragmentation to N‐methylene‐3‐butenyl‐amine ( 17 ). This unusual reactivity is ascribed to strain and to concomitant weakening of the N‐C4 bond in the bicyclic amine 1 .