Abstract: This process is intended to obtain clarithromycin. According to the process, it starts from the erythromycin A 9-oxime hydrochloride, which is transformed into clarithromycin by means of a synthetic sequence in which an acetal of the 9-oxime is initially formed. The use of the oxime hydrochloride permits that only the use of catalytic amounts of pyridine salts are necessary to favor the reaction. Next, the hydroxyls in positions 2′ and 4″ are protected with a silylating agent and the hydroxyl in position 6 is methylated; all this without the isolation of any reaction intermediate being necessary. Finally, the acetal and 2′ and 4″ silanes unprotection, followed by the deoximation yields clarithromycin with a high yield and a form which is easily applicable industrially.

Abstract: This process is intended to obtain clarithromycin. According to the process, it starts from the erythromycin A 9-oxime hydrochloride, which is transformed into clarithromycin by means of a synthetic sequence in which an acetal of the 9-oxime is initially formed. The use of the oxime hydrochloride permits that only the use of catalytic amounts of pyridine salts are necessary to favor the reaction. Next, the hydroxyls in positions 2′ and 4″ are protected with a silylating agent and the hydroxyl in position 6 is methylated; all this without the isolation of any reaction intermediate being necessary. Finally, the acetal and 2′ and 4″ silanes unprotection, followed by the deoximation yields clarithromycin with a high yield and a form which is easily applicable industrially.