Taïcir Ben Ayed

Addition of bromine to β'-(functional alkyl) α, β-unsaturated esters stereoselective synthesis of β-haloderivatives

Abstract A new convenient stereoselective synthesis of β-brominated β′-(functional alkyl) α,β-unsaturated esters has been developed by the reaction of tetraalkylammonium fluoride in HMPA with ethyl 2,3-dibromo 2-(functional alkyl) propionates which can be easily prepared by addition of bromine to β′-(functional alkyl) acrylates. An interpretation of the observed stereoselectivity is proposed.

A convenient synthesis of γ-functionalized cyclopentenones

The synthesis of γ-functionalized cyclopentenones was carried out in a few steps, starting firstly with the preparation of nitroketonic intermediates 2, which were readily transformed into 1,4-diketones using the Nef conversion. The intramolecular cyclization of the γ-diketones 3 in a basic medium, led to the functionalized cyclopentenones 4.