Solvent and substituent effects on conjugated eliminations in propargylic systems

F Le Strat, J Maddaluno

Index: Le Strat, Frederic; Maddaluno, Jacques Tetrahedron Letters, 2000 , vol. 41, # 28 p. 5367 - 5371

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Citation Number: 6

Abstract

The deprotonation of 4-methoxy-but-2-ynal diethyl acetal by n-butyllithium induces an acetylenic–allenic isomerization (in diethylether) or a conjugated elimination reaction (in THF), providing the corresponding 1, 4-dialkoxycumulene. An allenyllithium, that has been trapped as an allenylstannane, is proposed to be a common intermediate to both pathways. Also, the deprotonation of 4-dialkylamino-but-2-ynal diethyl acetals in the same conditions ...