Synthesis of isoprenoid natural products from β-keto esters

Abstract

The anions of β-keto esters were reacted with diethyl phosphorochloridate to yield the corresponding enol phosphate. These enol phosphates were coupled with lithium dimethylcuprate to give the resulting β-methyl α, β-unsaturated ester stereoselectively and in good yield. When combined with the β-alkylation of the β-keto ester dianions this overall sequence results in the stereoselective and regioselective incorporation of an isoprene moiety in a synthetic sequence. This transformation has been applied in the synthesis of ( E,E)-10-hydroxy-3,7-dimethyldeca-2,6-dienoic acid (butterfly compound), Latia luciferin, and mokupalide.