Ester homologation via .alpha.-bromo .alpha.-keto dianion rearrangement

Towards the Synthesis of the 4,19‐Diol Derivative of (–)‐Mycothiazole: Synthesis of a Potential Key Intermediate

“…Direct homologation following the method of Kowalski et al [30] provided degradation products. We chose to transform alcohol 17 into a leaving group and to substitute it with potassium cyanide (Scheme 7).…”

2.06 Formation of Enolates

“…65 These enolate formations occur without isomerization. [66][67][68][69] employed dibromomethyllithium (prepared in situ) to prepare an α-bromo ketone enolate at low temperatures. At higher temperatures and under extremely basic conditions, this enolate rearranged to give an ynolate.…”

Agrochemicals

“…The Claisen condensation with methyl formate and methylation with diazomethane lead finally to racemic oudemansin A. [48][49][50] Alternatively, the central synthetic building block can also be generated via a diastereoselective Ireland-Claisen rearrangement of butenyl methoxyacetate. Introduction of the styryl fragment results from a Horner-Wadsworth-Emmons reaction.…”