Obtention of 2,2-(diethoxy) vinyl lithium and 2-methyl-4-ethoxy butadienyl lithium by arene-catalysed lithiation of the corresponding chloro derivatives. Synthetic applications

Abstract

Vinylic lithium reagents 1 and 2 could be obtained by the title procedure from their chloro precursors 5 and 6 instead of the less stable corresponding bromo derivatives 3 and 4. Condensation with carbonyl compounds leads to interesting synthetic applications such as a two steps synthesis of retinal 13 from β-cyclocitral 10.