Bowen RD, Gallagher RT, Meyerson S. The structure and mechanism of formation of C5H 9O (+) from ionized phytyl methyl ether.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 1996;
7:205-208. [PMID:
24203243 DOI:
10.1016/1044-0305(95)00679-6]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/1995] [Revised: 10/26/1995] [Accepted: 11/01/1995] [Indexed: 06/02/2023]
Abstract
The recent proposal that ionized phytyl methyl ether [C16H33(CH3)C=CHCH2OCH 3 (+·) ] undergoes an allylic rearrangement to ionized isophytyl methyl ether [CH2=CHC(C16H33)(CH3)OCH 3 (+·) ] before elimination of an alkyl radical is discussed. Both literature precedent and new results in which the structure of the [M-C16H 33 (·) ](+) fragment ion is established by comparison of its collision-induced dissociation mass spectrum with the spectra of isomeric C5H9O(+) ions of known structure are inconsistent with this proposal. The forma Hon of CH3CH=CHCH=O(+)CH3 by loss of a γ-alkyl substituent without skeletal isomerization rather than CH2=CHC(CH3)=O(+)CH3 after allylic rearrangement is explained in terms of a mechanism that involves two 1,2-H shifts, followed by σ-cleavage of the resultant ionized enol ether, C16H33(CH3)CH-CH=CHOCH 3 (+·) .
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