13^2-氧代焦脱镁叶绿酸-a甲酯的E-环反应及其最大可见光吸收波长的变化

Reactions of E-ring of Methyl 132-oxo-pyropheophorbide-a and Changes of Maximum Absorptions Wavelength of Visible Light

以132-氧代焦脱镁叶绿酸-a甲酯1为起始原料,在碱性条件下重排成红紫素-18甲酯2,继续与盐酸羟胺的酰胺化反应得到红紫素-18内酰胺3;1与邻苯二胺的缩合反应生成苯并咪唑并红紫素-18甲酯4,与重氮甲烷的Tiffeneau-Demjanov重排反应分离出维尔啶(verdins)衍生物5.对132-焦脱镁叶绿酸-a甲酯1的外接E-环反应机理进行讨论,并解释和总结了所得叶绿素类二氢卟吩的最大可见光吸收波长的变化原因及规律.

Methyl 132-oxo-pyropheophorbide-a 1 is used as starting material and rearranged into purpurin-18 ester 2 in alkaline condition. Purpurin-18 amide 3 is obtained by further amidation reaction with hydroxylamine hudroehlo- ride. The condensation of 1 with phenylenediamine gives benzimidazolo-purpurin-18 methyl ester 4. Vidins 5 is separated in Tiffeneau-Demjanov rearrangement reaction of 1 with diazomethane. The reaction mechanisms about exocyclic E-ring of methyl 132-oxo-pyropheophorbide-a 1 are discussed, and the relavent reasons and regular pat- terns about varieties of the maximum absorption wavelength of visible light of chlorophyllous chlorins are explained and summarized.