C-3-吡唑啉基取代的叶绿素类二氢卟吩衍生物的合成

Synthesis of C-3-Pyrazolinyl-substituted Chlorins Related to Chlorophyll-a

以脱镁叶绿酸-a甲酯为起始原料,通过对E-环、3-位碳碳双键和20-位meso-氢的结构修饰,在二氢卟吩色基上构建和引进不同的官能团,并进一步利用其3-位乙烯基与重氮甲烷的1,3-偶极环加成反应,完成一系列C-3-吡唑啉基取代的叶绿素类二氢卟吩衍生物的合成.同时,讨论了叶绿素衍生物的1,3-偶极环加成反应的的区域选择性与立体选择性.所得新的叶绿素类二氢卟吩衍生物的化学结构均经UV,IR,1H NMR及元素分析得以证实.

Methyl pheophorbide-a was used as starting material and modified for the E-ring, the car- bon-carbon double bands at 3-position and 20-meso-hydrogen to construct and introduce different functional groups on the chlorin chromophore. The synthesis of a series of C-3-pyrazolinyl-substituted chlorins related to chlorophyll-a was fulfilled by the 1,3-dipolar cyclocaddition of the C-3-vinyl groups with diazomethane. The region- and stereo-selectiveties in 1,3-dipolar cyclocaddition of the chlorins were discussed. The struc- tures of new chlorophyll derivatives were characterized by UV, IR, 1H NMR spectra and elemental analysis.