Studies on pleuromutilin and some of its derivatives.

A number of derivatives of pleuromutilin (I) and of its degradation product, mutilin (II1, was prepared. The new monotosylation product of pleuromutilin (IIIc) served as the key substance for modification of the glycolic acid side chain. From the pleuromutilin monosuccinate (IIIk) water-soluble salts were obtained, among them the crystallized diethylaminoethanol salt that was investigated more closely. Some of the pleuromutilin derivatives showed antimicrobial activity.