Substituted 14-desoxy-mutilin compositions

This invention relates to new pleuromutilins of the formula: wherein either R1 is ethyl or vinyl, n is an integer from 2 to 5, x is sulphur, a group or a group =N-R4 I, wherein either Y and Z are both sulphur, or one of Y and Z is oxygen and the other is sulphur, and R4I is hydrogen or a group of the formula: wherein R1 is as defined above, each of R2 and R3 is alkyl of 1 to 10 carbon atoms, or R2 and R3 together with the nitrogen atom form a heterocycle of 5 to 7 ring members containing one nitrogen atom or one nitrogen atom and a further hetero member selected from sulphur, oxygen and a group =N-R5I, wherein R5I is alkyl of 1 to 5 carbon atoms or hydroxyalkyl of 1 to 4 carbon atoms, or R2 and R3 together with the nitrogen atom form a piperazinyl radical, the second nitrogen atom of which is substituted by a radical R5II, whereby R5II is (acyloxy of 2 to 5 carbon atoms)alkyl of 1 to 4 carbon atoms or (benzoyloxy)alkyl of 1 to 4 carbon atoms, or wherein R1 is as defined above, n is the number 2, R3 is alkyl of 1 to 10 carbon atoms, hydroxyalkyl of 1 to 4 carbon atoms, (acyloxy of 2 to 5 carbon atoms)alkyl of 1 to 4 carbon atoms or (benzoyloxy)alkyl of 1 to 4 carbon atoms, X is the group =N-R4II, and R2 together with R4II forms an ethylene bridge between both nitrogen atoms, and pharmaceutically acceptable acid addition salts and quaternary salts thereof. Processes for the preparation of such compounds are described. The compounds are antibiotics with an antibacterial effect.