New two-step sequence involving a hetero-Diels–Alder and a nonphenolic oxidative coupling reaction: a convergent access to analogs of steganacin
摘要:
A new family of analogs of steganacin, an important antimitotic compound, was accessed. It takes advantage of a completely stereoselective sequence of two key steps. The central dihydropyrane core is built by a highly diastereoselective and facially controlled hetero-Diels-Alder reaction. It is followed by a nonphenolic biaryl oxidative coupling with a complete atropo-stereoselectivity. It leads to a quick way to form cyclic biaryl lignans. (C) 2011 Elsevier Ltd. All rights reserved.
New two-step sequence involving a hetero-Diels–Alder and a nonphenolic oxidative coupling reaction: a convergent access to analogs of steganacin
摘要:
A new family of analogs of steganacin, an important antimitotic compound, was accessed. It takes advantage of a completely stereoselective sequence of two key steps. The central dihydropyrane core is built by a highly diastereoselective and facially controlled hetero-Diels-Alder reaction. It is followed by a nonphenolic biaryl oxidative coupling with a complete atropo-stereoselectivity. It leads to a quick way to form cyclic biaryl lignans. (C) 2011 Elsevier Ltd. All rights reserved.
R' = Me, Ar, CH2 Ar) and beta,gamma-unsaturated alpha-ketoesters (R = Ar) afforded heteroadducts with high levels of endo and facialselectivities. A complete reversal of facial differentiation was achieved by varying the Lewis acid, leading to the stereoselective formation of either endo-alpha or endo-beta adducts. [reaction: see text].
新的β-取代的N-乙烯基-1,3-恶唑烷-2-酮(具有R'= Me,Ar,CH2 Ar)与β,γ-不饱和α-酮酸酯([4 + 2]酸催化的杂环加成)之间( R = Ar)提供具有高水平的内和面选择性的杂加合物。通过改变路易斯酸可以完全逆转面部分化,从而导致内-α或内-β加合物的立体选择性形成。[反应:请参见文字]。
New two-step sequence involving a hetero-Diels–Alder and a nonphenolic oxidative coupling reaction: a convergent access to analogs of steganacin
作者:Mathieu Y. Laurent、Vivien Stocker、Valéry Momo Temgoua、Gilles Dujardin、Robert Dhal
DOI:10.1016/j.tetlet.2011.01.097
日期:2011.4
A new family of analogs of steganacin, an important antimitotic compound, was accessed. It takes advantage of a completely stereoselective sequence of two key steps. The central dihydropyrane core is built by a highly diastereoselective and facially controlled hetero-Diels-Alder reaction. It is followed by a nonphenolic biaryl oxidative coupling with a complete atropo-stereoselectivity. It leads to a quick way to form cyclic biaryl lignans. (C) 2011 Elsevier Ltd. All rights reserved.