Sefkow M, Kiffe M, Höfle G
Gesellschaft für Biotechnologische Forschung mbH, Abt. Naturstoffchemie, Germany.
Bioorg Med Chem Lett. 1998 Nov 3;8(21):3031-6. doi: 10.1016/S0960-894X(98)00546-0.
Epothilone A reacted with hydrohalic acids to C12-C13 halohydrin regioisomers (ratios: 2:1-4:1), whereas epothilone B gave under the same conditions the isomerically pure C12 halo C13 hydroxy derivative. With non-nucleophilic Brønstedt acids and with Lewis acids a highly solvent dependent product distribution and some unexpected rearrangement products were observed. Epothilone C bearing a double bond between C12 and C13 was regioselectively dihydroxylated or hydrogenated at that position.
埃坡霉素A与氢卤酸反应生成C12 - C13卤代醇区域异构体(比例为2:1 - 4:1),而埃坡霉素B在相同条件下生成异构纯的C12卤代C13羟基衍生物。对于非亲核布朗斯特酸和路易斯酸,观察到产物分布高度依赖于溶剂,并出现了一些意外的重排产物。在C12和C13之间带有双键的埃坡霉素C在该位置发生区域选择性二羟基化或氢化反应。