Stereoconvergent ‘one-pot’ tandem [2,3]-Wittig-anionic oxy-Cope rearrangement of acyclic bis-allylic ethers in the diastereoselective synthesis of substituted tetrahydropyrans
Acyclic stereocontrol via sequential and tandem [2,3]-Wittig-anionic oxy-Cope rearrangements
作者:Nicholas Greeves、Katya Jane Vines
DOI:10.1016/0040-4039(94)88230-4
日期:1994.9
Acyclic bis-allylic ethers undergo a stereoconvergent 'one-pot' tandem [2,3]-Wittig-anionic oxy-Cope (AOC) rearrangement to give the same δ,ε-unsaturated aldehyde, with Esyn stereochemistry, as that obtained by AOC rearrangement of isolated [2,3]-Wittig products.
An improved Williamson etherification of hindered alcohols promoted by 15-crown-5 and sodium hydride
作者:Helen C. Aspinall、Nicholas Greeves、Wai-Man Lee、Edward G. McIver、Peter M. Smith
DOI:10.1016/s0040-4039(97)00965-9
日期:1997.6
15-crown-5 greatly facilitates Williamson ether synthesis when sodium hydride base is used in THF solvent. This mild yet versatile procedure has been employed in the synthesis of new homochiral polyether ligands and bis-allylic ethers which are inaccessible by conventional methods. (C) 1997 Elsevier Science Ltd.