Open AccessPhotochemistry of Oximes III. The Photochemical Beckmann Rearrangement
Author(s) -
M. Cunningham,
L. S. Ng Lim,
George Just
Publication year - 1971
Publication title -
canadian journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.323
H-Index - 68
eISSN - 1480-3291
pISSN - 0008-4042
DOI - 10.1139/v71-479
Subject(s) - beckmann rearrangement , chemistry , yield (engineering) , methanol , ring (chemistry) , cyclohexanone oxime , photodissociation , oxime , cyclohexanone , photochemistry , medicinal chemistry , computational chemistry , organic chemistry , catalysis , materials science , metallurgy
Cycloalkanone oximes of ring-size four to fifteen are shown to yield lactams upon irradiation in methanol solution. Acyclic ketoximes similarly yield Beckmann-type products in methanol solution. Unlike the Beckmann rearrangement, unsymmetrically α-substituted cyclohexanone oximes give mixtures of approximately equal parts of both possible lactam isomers. The photolysis of oximes epimeric at the α-carbon gives products in which the α-center has retained its configuration. The results are interpreted in terms of a concerted breakdown of an oxazirane intermediate.