A new class of halogenated oxa[9]helicene derivatives along with dibromo spiro-lactone were synthesized in excellent yields, and the compounds were successfully characterized by different spectroscopic techniques (e.g. 1H and 13C NMR, HRMS spectroscopy and X-ray crystallography).
以优异的收率合成了新型的卤代氧杂[9] ic烯衍生物和二溴螺内酯,并通过不同的光谱技术(例如1 H和13 C NMR,HRMS光谱和X射线晶体学)成功地表征了这些化合物。。
Synthesis of oxa[9]helicene derivatives by cyclodehydration of 1,1′-bibenzo[c]phenanthrene-2,2′-diol using phosphorus pentoxide
derivatives, containing eight ortho-condensed benzene rings and one furan ring. 1,1′-Bibenzo[c]phenanthrene-2,2′-diols (HEBPOLs) afforded the corresponding oxa[9]helicenes by refluxing with phosphorous pentoxide (P2O5) in o-dichlorobenzene. Enantiomerically pure oxa[9]helicenes were also synthesized with retention of the configuration and enantiopurity (>98% ee) from the corresponding enantiomerically pure
建立了一个新的单步环化反应,用于合成含八个邻位稠合苯环和一个呋喃环的氧杂[9] hel烯衍生物。1,1'-联苯并[ c ]菲-2,2'-二醇(HEBPOLs)通过与五氧化二磷(P 2 O 5)在邻二氯苯中回流得到相应的oxa [9]螺旋烯。还从相应的对映体纯的HEBPOLs合成了对映体纯的oxa [9]螺旋烯,保留了构型和对映体纯度(> 98%ee)。
Synthesis of Enantiomerically Pure Oxa[9]helicene Derivatives by a Nucleophilic Cyclodehydration Reaction of Helical 1,1′-Bibenzo[c]phenanthrenylidene-2,2′-dione
Enantiomerically pure 9-substituted 11-oxa[9]helicene derivatives have been synthesized through furan-ring formation by a nucleophilic cyclodehydration reaction of enantiomerically pure helical polycondensed 2,2′-diphenoquinone derivatives (1,1′-bibenzo[c]phenanthrenylidene-2,2′-diones). (P)-2,2′-diphenoquinone derivatives afforded (P)-oxa[9]helicenes, whereas (M)-2,2′-diphenoquinone derivatives afforded
New oxa[9]helicenes which possess one furan ring have been readily prepared by reactive helical quinone with Lawesson's reagent or phosphorus pentasulfide in good yields. The versatility of this protocol has been demonstrated with various substituted helical quinones. (C) 2011 Elsevier Ltd. All rights reserved.