75343-99-6Relevant academic research and scientific papers
Deshydratation des diols-1,2α,β-ethyleniques IV: role de la stereomutation des carbocations allyliques α-hydroxyles sur l'orientation des reactions observees
Dana, Gilbert,Gharbi-Benarous, Josyane,Thuan, Sa Le Thi
, p. 1451 - 1462 (2007/10/02)
The allylic carbocations formed during the dehydration of diols of type A are found to react by five different processes: three nucleophilic attacks (by solvent at the β or δ positions, or by the intramolecular hydroxyl group at δ), a degradation reaction between Cα and Cβ and the classical pinacol rearrangement.Nucleophilic attack at the carbon δ is a very efficient reaction and sometimes (for monosubstituted substrates in β, γ or δ) gives quasi-exclusive products: a ketone for the reaction with H2O in δ or a 2,5-dihydrofuran product for the intramolecular reaction.In the case of γ and δ disubstituted carbocations, the selectivity is less and we show that it is possible to analyze the different steric effects commanding the stereomutation equilibrium of the allylic carbocation and so determining the orientation in the dehydration.
