Does the dieckmann condensation occur in the gas phase?
作者:Mark J. Raftery、John H. Bowie
DOI:10.1002/oms.1210231008
日期:1988.10
AbstractBurinsky and Cooks1 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. MeOCOC̄HCH2R → [MeO(OCCHCH2R)] → OCCHC̄HR + MeOH. Evidence is presented which supports the Dieckmann mechanism for adipates. For example, MeOCOC̄(Me)CH2CH2CD(Me)CO2Me should eliminate MeOD in a Dieckmann condensation, but MeOH by the alternative mechanism outlined above. Experimentally, MeOD is lost exclusively. Similarly, MeOCOC̄DCH2CH2C(Me)2CO2Me also loses MeOD, consistent with a Dieckmann process.