| abstract |
A compound of the formula: ##STR1## wherein R is 2-methylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, n-pentyl, an alkyl group of 6 or 7 carbon atoms, or an alkenyl group of 2 to 7 carbon atoms, or a pharmaceutically acceptable salt thereof and processes for preparing the same are provided. The compound can orally be applied as antibiotics having improved absorbability. |