LiTMP-LiBr complex-induced lateral lithiation and cross ester condensation: direct access to isocoumarins from 2-methoxy o-toluate esters†
Abstract
A LiTMP-LiBr complex facilitates a novel cross-ester coupling of 2-methoxy o-toluate esters to directly yield isocoumarin without the formation of any carbonyl intermediate. Aggregation plays a pivotal role in driving proximity-induced lateral lithiation and expediting acylation. In addition to many natural product precursors, the synthesis of (+)- and (−)-lunatinins is shown.