The synthesis of ring-contractedderivatives of erythromycin A via intramolecular transesterification under microwave irradiation of 8,9-anhydroerythromycin A 6,9-hemiketal and its derivatives is described. It was found that microwave irradiation could significantly improve the yields and shorten the reaction times under either solvent-containing (method A) or solvent-free (method B) conditions.
描述了在 8,9-脱水红霉素 A 6,9-半缩酮及其衍生物的微波照射下通过分子内酯交换合成红霉素 A 的环收缩衍生物。结果表明,在含溶剂(方法 A)或无溶剂(方法 B)条件下,微波辐射可以显着提高产率并缩短反应时间。
Motilides, macrolides with gastrointestinal motor stimulating activity. I. O-substituted and tertiary N-substituted derivatives of 8,9-anhydroerythromycin A 6,9-hemiacetal.
9-anhydroerythromycin A 6,9-hemiacetal (1), which showed gastrointestinal motor stimulating (GMS) activity 10 times more potent than that of erythromycin A (EM-A), were undertaken to search for derivatives having stronger GMS activity and no antimicrobial activity; details are described in this and a subsequent paper. Displacement of a methyl group of the dimethylamino group of 1 with an ethyl group