反应详情

According to such a synthesis an enol-ether function (2) is generated in the molecule of erythromycin A (1) and subsequently the N-dimethyl group of desosamine is protected as N-oxide (3) to avoid the partial or total N-demethylation of the basic sugar during the fluorination; fluorination of (3) with trifluoromethyl hypofluorite or perchloryl fluoride, followed by hydrogenolysis, gives (8S)-8-fluoroerythromycin A (5). As a matter of fact, by operating according to the disclosure of the second Application erythromycin A can be converted into (8S)-8-fluoroerythromycin A, with a yield of about 35% in four subsequent steps (scheme II):