M. Alajarin et al., Conversion of N-acyl-4-acyloxy-beta-lactams into 1,3-oxazin-6-ones: Two consecutive pseudopericyclic processes, ORG LETT, 2(7), 2000, pp. 965-968
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N-Acyl-4-acyloxy-beta-lactams are converted into 1,3-oxazin-6-ones under ba
sic conditions. This transformation is believed to proceed via N-acylazeton
es, which rearrange to the final products by a sequence of two electrocycli
c processes. The calculated (RHF and B3LYP) transition structures of both c
oncerted reactions are shown to present characteristic pseudopericyclic orb
ital topologies.