La cohalogenation des olefines dans l'oxyde d'ethylene : Nouvel acces aux ethers vinylallyliques.
作者:J Rodriguez、J.P Dulcere、M Bertrand
DOI:10.1016/s0040-4039(00)85914-6
日期:1983.1
RODRIGUEZ, J.;DULCERE, J. P.;BERTRAND, M., TETRAHEDRON LETT., 1983, 24, N 41, 4423-4424
作者:RODRIGUEZ, J.、DULCERE, J. P.、BERTRAND, M.
DOI:——
日期:——
Cohalogenation of Alkenes in Ethylene Oxide: Efficient Methodology for the Preparation of Allyl Vinyl Ether Precursors of γ,δ-Unsaturated Aldehydes
作者:Jean-Pierre Dulcère、Jean Rodriguez
DOI:10.1055/s-1993-25872
日期:——
An investigation of the cohalogenation-dehydrohalogenation sequence as a method for the preparation of allyl vinyl ethers from simple olefins has been performed. Alkenes 1a-k react with bromine or chlorine in the presence of ethylene oxide at - 80°C to form β,β′-dihalo ethers 2a-k regio- and stereoselectively in high yields. Two of these β,β′-dihalo ether intermediates were selectively monodehydrohalogenated by potassium tert-butoxide to give 2-haloalkyl vinyl ethers in almost quantitative yields. Use of an excess of base produces allyl vinyl ethers 3a-k in good yields. Thermal rearrangement of the latter converts them into the corresponding γ,δ- unsaturated aldehydes 4a-j.