system of antimonypentachloride, chlorotrimethylsilane and tin(II) iodide, α-substituted cyclic ethers are stereoselectively prepared from lactones by successive treatment with 1-(t-butyldimethylsiloxy)-1-ethoxyethene and silyl nucleophiles such as triethylsilane, allyltrimethylsilane and trimethylsilyl cyanide. These catalysts also promote the reaction of γ-, δ-, and e-trimethylsiloxy carbonyl compounds
Lewis Acid Mediated “<i>endo-dig</i>” Hydroalkoxylation–Reduction on Internal Alkynols for the Stereoselective Synthesis of Cyclic Ethers and 1,4-Oxazepanes
作者:Santosh J. Gharpure、Dharmendra S. Vishwakarma、Santosh K. Nanda
DOI:10.1021/acs.orglett.7b03241
日期:2017.12.15
Lewisacidmediated 5/6/7-endo-dig hydroalkoxylation–reduction cascade on internal alkynols gave an expedient, stereoselective synthesis of cyclic ethers and 1,4-oxazepanes. The strategy has been extended to the first examples of hydroalkoxylation–alkyne Prins-type cyclization cascade of alkyne-tethered alkynols, giving access to oxa-bicyclic scaffolds. This method was used as the key step in the stereoselective
Stereoselective synthesis of side chain-functionalized tetrahydropyrans from 5-hexenols
作者:Patrick Fries、Melanie Kim Müller、Jens Hartung
DOI:10.1016/j.tet.2013.12.019
日期:2014.2
products of 6-exo-bromocyclization, as exemplified by synthesis of diastereomerically pure 2,4,6-substituted tetrahydropyrans. The cobalt method extends to intermolecular alkene/alkanol cross-coupling and to multi-component reactions between dimethyl fumarate, CHD, a 5-hexenol, and dioxygen, providing α-tetrahydropyranyl-2-methyl succinates in synthetically useful yields.
A Convenient Synthesis of Cyclic Ethers from Siloxy Carbonyl Compounds
作者:Koichi Homma、Teruaki Mukaiyama
DOI:10.1246/cl.1989.259
日期:1989.2
Five–seven membered cyclic ethers are prepared by one-pot procedure in good yields from γ-, δ-, and e-siloxy carbonyl compounds, respectively, on treatment with silyl nucleophiles (triethylsilane, allyltrimethylsilane, trimethylsilyl cyanide, etc.) in the presence of a catalytic amount of trityl hexachloroantimonate, or a catalyst system of antimony pentachloride, chlorotrimethylsilane and tin (II)
分别用甲硅烷基亲核试剂(三乙基硅烷、烯丙基三甲基硅烷、三甲基氰化氰化物等)处理后,分别由γ-、δ-和ε-甲硅烷氧基羰基化合物以高产率通过一锅法制备五七元环醚。存在催化量的六氯锑酸三苯甲基酯,或五氯化锑、氯三甲基硅烷和碘化锡 (II) 的催化剂体系。
A process for the production of new CCR2 receptor antagonists and intermediates thereof