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Does the dieckmann condensation occur in the gas phase?
Author(s) -
Raftery Mark J.,
Bowie John H.
Publication year - 1988
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210231008
Subject(s) - condensation , chemistry , adipate , deprotonation , methanol , stereochemistry , organic chemistry , thermodynamics , polymer chemistry , physics , ion
Burinsky and Cooks 1 have reported that deprotonated dimethyl adipate eliminates methanol via a gas‐phase Dieckmann condensation. This is in contrast to the behaviour of simple methyl ester enolates which lose MeOH by a different mechanism, e.g. MeOCOC̄HCH 2 R → [Me O (OCCHCH 2 R)] → OCCHC̄HR + MeOH. Evidence is presented which supports the Dieckmann mechanism for adipates. For example, MeOCOC̄(Me)CH 2 CH 2 CD(Me)CO 2 Me should eliminate MeOD in a Dieckmann condensation, but MeOH by the alternative mechanism outlined above. Experimentally, MeOD is lost exclusively. Similarly, MeOCOC̄DCH 2 CH 2 C(Me) 2 CO 2 Me also loses MeOD, consistent with a Dieckmann process.