| 摘要 |
<p>Erythromycin A, deriv. (I) is selectively methylated at position 6 hydroxy gp. by first converting to the 9-oxime (II), and reacting the prod. with a methylating agent to produce (III). - Hydroxylamines include hydroxylamine itself, O-alkylhydroxylamine, O-alkenylhydroxylamine, O-aralkylhydroxylamine and O-(substd. alkyl) hydroxylamine. Met-ylating agents include methyl iodide, methyl bromide, dimethyl sulphate, methyl p-toluenesulphonate and methyl methanesulphonate. - Derivs. of erythromycin A which may be used as starting materials include those where a methyl gp. on the 3'-dimethylamino gp. is replaced by alkoxycarbonyl, cycloalkoxycarbonyl, alkoxyalkoxycarbonyl, haloalkoxycarbonyl, unsatd. alkoxycarbonyl, substd. benzyloxycarbonyl, substd. phenoxycarbonyl, the H of the 2'-hydroxy gp. is replaced by the above oxycarbonyl gps. or by acyl.</p> |
