Unimolecular rearrangements of ketene-O,O-acetals and fragmentations occurring in the gas phase.

J Mass Spectrom

Departamento de Química Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado 14-740, México, D. F., 07000 Mexico.

Published: May 2011


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Article Abstract

Gas phase skeletal rearrangements of regioisomeric 3-cyano-2-methoxy-3a-alkylfuro[2,3-b]- and [3,2-b]indoles were evidenced by product ions [M-32](+•), consistent with loss of methanol, on electron ionization in their mass spectra. The rearranged products occurring in gas phase were demonstrated to have elemental composition and fragmentation properties identical to those of authentic samples of 2-indolyl cyanomalonates. Isotopic labeling experiments support the formation mechanism of the [M-32](+•) ion. Additional thermal gas-phase reaction products were characterized by comparison with an authentic sample.

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