Mg(OMe)₂ promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters to synthesize γ-ketone esters

Abstract

This work concerns the Mg(OMe) promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters with TMEDA as an additive. The isomerization proceeded under mild conditions and afforded γ-keto esters in high yield (up to 96%) within 2 h. Both (Z)- and (E)-γ-hydroxy-α,β-alkenoic esters were tolerated under the reaction conditions. This transformation involves the in situ formation of a dienolate intermediate from the easily accessible γ-hydroxy-α,β-alkenoic ester. The in situ generated dienolate can react with benzaldehyde and undergo a practical, useful tandem allylic isomerization-Aldol reaction to afford more functionalized compounds.

Silylpyrrole Oxidation En Route to Saxitoxin Congeners Including 11-Saxitoxinethanoic Acid

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Esterification of Aryl/Alkyl Acids Catalysed by N-bromosuccinimide under Mild Reaction Conditions

“…Methyl 4-(4-chlorophenyl)-4-oxobutanoate ( 23a ) [ 72 ] . Synthesized according to the general procedure.…”

Synthesis and Evaluation of Structurally Diverse C-2-Substituted Thienopyrimidine-Based Inhibitors of the Human Geranylgeranyl Pyrophosphate Synthase

“…The racemic intermediate 24 was synthesized as previously reported. 57 1 H NMR (500 MHz, DMSOd 6 ) δ 12.83 (s, 1H), 7.49−7.20 (m, 5H), 4.77 (s, 1H), 3.31 (s, 3H). 13 C NMR (126 MHz, DMSO-d 6 ) δ 171.8, 137.2, 128.4, 128.3, 127.1, 81.6, 56.7, 40.0, 39.9, 39.7, 39.5, 39.4, 39.2, 39.0.…”