Synthesis and Separation of the Clarithromycin A<i<E</i<-9-<em<O</em<-Methyl Oxime

To control the commercial production of clarithromycin, clarithromycin A(<em<E</em<)9-<em<O</em<-methyl oxime was synthesized using clarithromycin A oxime as the raw material by three steps:protection of 2′-OH and 4″-OH with TMS, methylation and de-protection of TMS. The structure was identified by <sup<1</sup<H NMR, <sup<13</sup<C NMR and HPLC analysis was conducted. Experimental results show that the reactions are greatly affected by catalyst, solvent and pH value. The parameters of HPLC are as follows. The mobile phase is ACN/KH<sub<2</sub<PO<sub<4</sub< aqueous solution (<em<V/V</em<=45/55), wavelength is 210 nm, temperature is 30 ℃ and the velocity of flow is 1.0 mL/min. This synthesized compound is of benefit to control the commercial production of clarithromycin.