P-61 非直結型ビステトラヒドロフランアセトゲニンの立体化学について(ポスター発表の部)

概要

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Annonaceous acetogenins have attracted much interest in these years because of their potent biological activities such as antitumor and insecticidal properties. These acetogenins can be classified into three groups, i.e., mono-tetrahydrofurans, adjacent bis-tetrahydrofurans and non-adjacent bis-tetrahydrofurans. Although the configuration of the multiple stereogenic centers of the first two groups were reported previously, the stereochemical issue of the last group, non-adjacent bis-tetrahydrofurans has not been challenged. We have now established the configuration of all the stereogenic centers of non-adjacent tetrahydrofurans, squamostatins A-E, which have been isolated from the seeds of A nnona squamosa. First, the relative stereochemistry of squamostatins A-E have been firmly established by comparing their ^<13>C NMR data with those of the stereochemically defined synthetic model mono-tetrahydrofurans. Then, the absolute configuration of the stereogenic centers has been determined by comparing the (R)-MTPA ester derivatives of the five acetogenins with those of the optically active model mono-tetrahydrofurans, focusing on the chemical shifts of H-12 and H-24. It has been concluded from these NMR comparative studies that squamostatins A, B and D have 12R, 15S, 16S, 19R,20R,23R,24S configuration, whereas squamostatins C and E have 12R, 15S, 16S, 19R, 20R,23R,24R stereochemistry.
天然有機化合物討論会の論文
1994-09-20