Gas-phase chemistry of acylium ions: Seven-to-five ring contraction of 1,3-dioxepane and 1,3-dioxep-5-ene

Tapio Kotiaho, Luiz Moraes, Marcos Eberlin

Research output: Contribution to journalArticleScientificpeer-review

11 Citations (Scopus)

Abstract

As shown by pentaquadrupole triple‐stage mass spectrometric and 18O‐labeling experiments, two seven‐membered cyclic acetals, 1,3‐dioxepane and 1,3‐dioxep‐5‐ene, fail to react by transacetalization with the gaseous acylium ions CH3C+=O and (CH3)2NC+=O. Instead, a novel and less exothermic but more kinetically favored reaction, seven‐to‐five ring contraction, occurs predominantly, and to great extents with the most reactive acylium ion, (CH3)2NC+=O. 1,3‐Dioxepane yields O‐acylated tetrahydrofurans; 1,3‐dioxep‐5‐ene yields O‐acylated 2,5‐dihydrofurans.
Original languageEnglish
Pages (from-to)670-676
Number of pages7
JournalJournal of Mass Spectrometry
Volume34
Issue number6
DOIs
Publication statusPublished - 1999
MoE publication typeA1 Journal article-refereed

Fingerprint

Gases
Ions
Furans
Acetals
Experiments

Cite this

Kotiaho, Tapio ; Moraes, Luiz ; Eberlin, Marcos. / Gas-phase chemistry of acylium ions : Seven-to-five ring contraction of 1,3-dioxepane and 1,3-dioxep-5-ene. In: Journal of Mass Spectrometry. 1999 ; Vol. 34, No. 6. pp. 670-676.
@article{af7e7f1508124a8797a4c09427ec9b53,
title = "Gas-phase chemistry of acylium ions: Seven-to-five ring contraction of 1,3-dioxepane and 1,3-dioxep-5-ene",
abstract = "As shown by pentaquadrupole triple‐stage mass spectrometric and 18O‐labeling experiments, two seven‐membered cyclic acetals, 1,3‐dioxepane and 1,3‐dioxep‐5‐ene, fail to react by transacetalization with the gaseous acylium ions CH3C+=O and (CH3)2NC+=O. Instead, a novel and less exothermic but more kinetically favored reaction, seven‐to‐five ring contraction, occurs predominantly, and to great extents with the most reactive acylium ion, (CH3)2NC+=O. 1,3‐Dioxepane yields O‐acylated tetrahydrofurans; 1,3‐dioxep‐5‐ene yields O‐acylated 2,5‐dihydrofurans.",
author = "Tapio Kotiaho and Luiz Moraes and Marcos Eberlin",
note = "Project code: K9SU00137",
year = "1999",
doi = "10.1002/(SICI)1096-9888(199906)34:6<670::AID-JMS819>3.0.CO;2-H",
language = "English",
volume = "34",
pages = "670--676",
journal = "Journal of Mass Spectrometry",
issn = "1076-5174",
publisher = "Wiley-Blackwell",
number = "6",

}

Gas-phase chemistry of acylium ions : Seven-to-five ring contraction of 1,3-dioxepane and 1,3-dioxep-5-ene. / Kotiaho, Tapio; Moraes, Luiz; Eberlin, Marcos.

In: Journal of Mass Spectrometry, Vol. 34, No. 6, 1999, p. 670-676.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Gas-phase chemistry of acylium ions

T2 - Seven-to-five ring contraction of 1,3-dioxepane and 1,3-dioxep-5-ene

AU - Kotiaho, Tapio

AU - Moraes, Luiz

AU - Eberlin, Marcos

N1 - Project code: K9SU00137

PY - 1999

Y1 - 1999

N2 - As shown by pentaquadrupole triple‐stage mass spectrometric and 18O‐labeling experiments, two seven‐membered cyclic acetals, 1,3‐dioxepane and 1,3‐dioxep‐5‐ene, fail to react by transacetalization with the gaseous acylium ions CH3C+=O and (CH3)2NC+=O. Instead, a novel and less exothermic but more kinetically favored reaction, seven‐to‐five ring contraction, occurs predominantly, and to great extents with the most reactive acylium ion, (CH3)2NC+=O. 1,3‐Dioxepane yields O‐acylated tetrahydrofurans; 1,3‐dioxep‐5‐ene yields O‐acylated 2,5‐dihydrofurans.

AB - As shown by pentaquadrupole triple‐stage mass spectrometric and 18O‐labeling experiments, two seven‐membered cyclic acetals, 1,3‐dioxepane and 1,3‐dioxep‐5‐ene, fail to react by transacetalization with the gaseous acylium ions CH3C+=O and (CH3)2NC+=O. Instead, a novel and less exothermic but more kinetically favored reaction, seven‐to‐five ring contraction, occurs predominantly, and to great extents with the most reactive acylium ion, (CH3)2NC+=O. 1,3‐Dioxepane yields O‐acylated tetrahydrofurans; 1,3‐dioxep‐5‐ene yields O‐acylated 2,5‐dihydrofurans.

U2 - 10.1002/(SICI)1096-9888(199906)34:6<670::AID-JMS819>3.0.CO;2-H

DO - 10.1002/(SICI)1096-9888(199906)34:6<670::AID-JMS819>3.0.CO;2-H

M3 - Article

VL - 34

SP - 670

EP - 676

JO - Journal of Mass Spectrometry

JF - Journal of Mass Spectrometry

SN - 1076-5174

IS - 6

ER -