Direct generation of lithium homoenolates from 3-aryl α,β-unsaturated ketones or esters by an arene-catalysed lithiation: Synthesis of substituted tetrahydrofurans and γ-butyrolactones
1997; Elsevier BV; Volume: 53; Issue: 7 Linguagem: Inglês
10.1016/s0040-4020(96)01155-6
ISSN1464-5416
AutoresEmma Alonso, Diego J. Ramón, Miguel Yus,
Tópico(s)Cyclopropane Reaction Mechanisms
ResumoThe reaction of α,β-unsaturated ketones 1 with an excess of lithium powder, a catalytic amount of naphthalene (4 %) and different carbonyl compounds in the presence of boron trifluoride in THF at −78 – 0°C yields, after treatament with silyl nucleophile and final hydrolysis, the expected substituted tetrahydrofurans 5. Similar methodology applied to β-aryl acrylic esters 6, but without using boron trifluoride or silyl reagents yields the corresponding lactones 7.
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