Motilides, macrolides with gastrointestinal motor stimulating activity. II. Quaternary N-substituted derivatives of 8,9-anhydroerythromycin A 6,9-hemiacetal and 9,9-dihydroerythromycin A 6,9-epoxide.
for antimicrobial activity and gastrointestinalmotorstimulating (GMS) activity in the dog (in vivo). The GMS activity is enhanced markedly when small alkyl halides and unsaturated alkyl halides such as allyl bromide and propargyl bromide are added to the dimethylamino group of 1. Among them, N-propargyl-8,9-anhydroerythromycin A 6,9-hemiacetal bromide (3) exhibits GMS activity 2890 times stronger
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