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Die B ECKMANN ‐Umlagerung und Fragmentierung von optisch aktiven α‐trisubstituierten Ketoximtosylaten
Author(s) -
Fischer H. P.
Publication year - 1965
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.19650480609
Subject(s) - chemistry , alkyl , medicinal chemistry , heterolysis , stereochemistry , amide , fragmentation (computing) , organic chemistry , catalysis , computer science , operating system
The solvolyses of optically pure (−)‐ anti ‐2‐methyl‐2‐phenyl‐butyrophenonoxime tosylate and anti ‐3‐methyl‐3‐phenyl‐2‐pentanonoxime tosylate in methanol and chloroform have been studied. In methanol rearrangement to amide with retained configuration of the migrating group is accompanied by fragmentation to predominantly inverted 2‐phenyl‐2‐methoxy‐butane. N‐Alkyl‐nitrilium salts are common intermediates for rearrangement and fragmentation. Since the heterolysis of N‐alkyl nitrilium ions is energetically related to S N 1 reactions of alkyl halogenides or alkyl esters, the stereochemical course has been interpreted in terms of D OERING 's mechanistic hypothesis for endothermic S N 1 reactions.