Staudinger reactions of unsymmetrical cyclic ketenes: a synthetically useful approach to spiro β-lactams and derivatives. Reaction mechanism and theoretical studiesElectronic supplementary information (ESI) available: Spectral data for compounds 4b–4m and 5b–5d and Cartesian coordinates and energies (hartrees) of zwitterionic intermediates (IZ1, IZ2, IZ3, and IZ4) and transition structures (TS1, TS2, TS3 and TS4). See http://www.rsc.org/suppdata/p1/b1/b103279h/
2002 ◽
pp. 571-576
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