| Abstract |
Ecteinascidin770 (Et770) and ecteinascidin786 (Et786) are potent cytotoxic tris-tetrahydroisoquinoline alkaloids isolated from the Thai tunicate, Ecteinascidia thurstoni. Et786 is the sulfoxide derivative of Et770 and possesses lower cytotoxic activity than Et770. Therefore, conversion of Et786 to Et770 is necessary. The reduction of the sulfoxide group in Et786 with a silane reducing agent (PhSiH3) catalyzed by a high-valent oxo-rhenium complex (ReOCl3(PPh3)2) was performed. The result showed that 100 mol% of PhSiH3 and 50 mol% of ReOCl3(PPh3)2 were suitable for the reduction reaction. In this presentation, solvent effect for the reaction was comparatively studied by using tetrahydrofuran, dichloromethane, chloroform, toluene and benzene. All aprotic solvents were effective for the reductive reaction and the reaction in tetrahydrofuran solution produced the highest yield of Et770 (74 % yield), based on HPLC analysis. |
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Journal Publication
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