By treatment of 8-hydroxyerythromycin A in an aprotic solvent with ethylene carbonate in the presence of K
2CO
3, two cyclic carbonates of 8-hydroxyerythromycin A with molecular formulae of C
38H
65NO
15 and C
39H
63NO
16, respectively, were obtained. Analytical, spectral and chemical data indicated their structures to be the 11, 12-cyclic carbonate of 8-hydroxyerythromycin A and the 8, 9; 11, 12-dicyclic dicarbonate of 8-hydroxyerythromycin A 6
9-hemiketal, respectively. The respective compounds have antibacterial activities against
Bacillus pumilus (in erythromycin A units) corresponding to 500μg/mg and 1, 250μg/mg. Similar treatment of the methyl
9 6-ketal of 8-hydroxyerythromycin A yields the 11, 12-cyclic carbonate. Acid hydrolysis of the latter is another route providing the 11, 12-cyclic carbonate of 8-hydroxyerythrornycin A, mentioned above.
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